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M17 - PRANAVAHA SROTOVIKARA

Department of Kaumarabhritya - PG Scholar Notes

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UNIT 2: UPPER RESPIRATORY TRACT INFECTIONS (URTI)

Pranavaha Srotovikara II

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1. RHINITIS (Pratishyaya)

Ayurvedic Correlation

• Samanya Nidana (Hetu): Sheetha sevana (cold exposure), Dhooma sevana, Rajopavastha (exposure to dust/allergens), Divaswapna, Ajirna, Vegavarodha (suppression of natural urges - sneezing, tears)
• Dosha: Primarily Kapha-Vata, with Pitta involvement in infectious forms
• Srotas involved: Pranavaha srotas, Rasavaha srotas

Nidana Panchaka

Samprapti Vighatana

Types (Charaka - 5 types of Pratishyaya)

1. Vataja - thin, watery, frothy discharge; excessive sneezing; headache; hoarseness
2. Pittaja - yellowish, purulent discharge; burning sensation; fever
3. Kaphaja - thick, white, copious discharge; heaviness; loss of smell
4. Tridoshaja (Sannipataja) - mixed features; severe
5. Kshataja/Dushta Pratishyaya - chronic/complicated; foul-smelling discharge; ulceration

Contemporary Clinical Notes

• Definition: Inflammation of nasal mucous membranes; classified as Allergic (seasonal/perennial) or Non-Allergic (infectious, vasomotor, drug-induced)
• Epidemiology: Affects 10-30% of children and adults
• Causative agents (Infectious): Rhinovirus (most common, 15-20%), Coronavirus, Parainfluenza, RSV, Adenovirus
• Allergic Rhinitis: IgE-mediated Type I hypersensitivity; common allergens - dust mites, pollen, animal dander
• Symptoms: Nasal congestion, rhinorrhea, sneezing paroxysms, nasal pruritus, post-nasal drip, watery eyes
• Diagnosis: Clinical; skin prick test / specific IgE for allergic type; nasal cytology (eosinophils in allergy)
• Complications: Sinusitis, Otitis media, Adenoid hypertrophy, Asthma exacerbation

Chikitsa (Management)

• Snehana - Anu taila Nasya (medicated nasal drops)
• Swedana - Steam inhalation (Tula sweda), Shashtika shali pinda sweda
• Shodhana - Vamana (Kapha dosha), Nasya karma (Seka, Pratimarsha)
• Shamana aushadha:
  • Vataja: Dashamoola kashaya, Vyaghri haritaki
  • Kaphaja: Trikatu churna, Sitopaladi churna, Pippali
  • Pittaja: Chandrakala rasa, Triphala, Guduchi
  • Key formulations: Sitopaladi churna, Anu taila, Shadanga paneeya, Trikatu, Haridra khanda

• Antihistamines (cetirizine, loratadine) - for allergic type
• Intranasal corticosteroids - first-line for persistent allergic rhinitis (most effective)
• Decongestants (phenylephrine, oxymetazoline - short-term only)
• Saline nasal irrigation
• Allergen immunotherapy for refractory allergic rhinitis
• Antibiotics only if bacterial superinfection (sinusitis, otitis media)

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2. PHARYNGITIS (Gala Shotha / Gala Roga)

Ayurvedic Correlation

• Nidana: Atiushna/Atisheetha bhojana, Swar atiyoga (voice overuse), Dhooma, Raja sevana, Vegavarodha (sneezing), Kruraprakruti
• Dosha: Primarily Vata-Kapha; Pittaja in febrile/exudative types
• Srotas: Pranavaha, Annavaha srotas

Nidana Panchaka

Samprapti

Microbial Causes (Tintinalli's Emergency Medicine)

Clinical Features

• Viral: Gradual onset; associated coryza, cough, mild fever; vesicular/petechial palate pattern
• Bacterial (GABHS): Sudden onset sore throat; high fever; tonsillar exudate; anterior cervical lymphadenopathy; absence of cough; scarlatiniform rash (Scarlet fever); strawberry tongue; Pastia's lines
• Incubation period: 2-5 days for GABHS
• Centor/McIsaac Score (for predicting GABHS):
  • Tonsillar exudate (+1)
  • Tender anterior cervical LN (+1)
  • Fever >38°C (+1)
  • Absence of cough (+1)
  • Age 3-14 yr (+1), >45 yr (-1)
  • Score ≥3: treat empirically or culture

Diagnosis

• Throat culture (gold standard - 5% sheep blood agar; sensitivity 96%)
• Rapid Antigen Detection Test (RADT) - sensitivity 60-80%, specificity 90%
• ASO titre (retrospective)

Complications

• Peritonsillar abscess (Tonsil Vidradhi)
• Retropharyngeal abscess
• Otitis media
• Rheumatic fever (M protein cross-reactivity)
• Post-streptococcal glomerulonephritis

Chikitsa

• Gandusha (oil pulling/gargling): Dashana Samskara churna, Triphala decoction, Patoladi kwatha
• Kavala (gargling): Vacha, Yashthimadhu, Haridra in warm water
• Pratisarana (application): Yashthimadhu + Madhu to throat
• Nasya: Anu taila
• Shamana:
  • Kaphaja: Sitopaladi + Trikatu + Tankan bhasma
  • Pittaja: Kama Dudha, Pravala Pishti, Chandanadi churna
  • Vataja: Dashamoola kashaya, Agastya haritaki
• Leha preparations: Kantakari avaleha, Vasavaleha

• Viral: Symptomatic - analgesics (paracetamol/ibuprofen), warm fluids, lozenges
• Bacterial (GABHS): Phenoxymethylpenicillin (Pen-V) for 10 days (DOC); Amoxicillin; Azithromycin for penicillin allergy
• Goal: Prevent rheumatic fever (must start within 9 days of symptom onset)
• Avoid antibiotics if score <2 (McIsaac)

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3. ADENOID HYPERTROPHY (Tundikeri / Galashundika)

Ayurvedic Correlation

• Anatomical site: Adenoids = Nasopharyngeal tonsil = part of Waldeyer's ring
• Ayurvedic reference: Tundikeri (tonsil-adenoid complex inflammation) in Charaka, Sushruta
• Dosha: Kapha predominant; Vata-Kapha in obstruction
• Nidana: Atisheeta sevana, recurrent infections, nutritional deficiency, Kapha-vardhaka ahara

Nidana Panchaka

Clinical Notes (Textbook of Family Medicine 9e)

• Common in children; adult adenoid hypertrophy should raise suspicion of lymphoproliferative disorder or HIV
• Causes: Chronic/recurrent nasal obstruction, rhinorrhea, snoring, cough, otitis media
• Adenoid facies: Elongated narrow face, open-mouth breathing, high-arched palate - consequence of long-standing nasal obstruction
• Adenoid hypertrophy can cause sinusitis secondary to nasal obstruction, mucus stasis, and infection
• Chronic adenoiditis can mimic sinusitis (symptoms often identical, disorders coexist)
• Diagnosis: Clinical; lateral neck X-ray confirms (shows soft tissue shadow encroaching on nasopharynx)
• Eustachian tube dysfunction → Conductive hearing loss → Glue ear (Otitis media with effusion)

Chikitsa

• Conservative: Nasya with Shadbindu taila, Anu taila; Dhoomapana (medicated smoke inhalation); Gandosha with Triphala; Trikatu, Sitopaladi internally; Rasayana - Chyavanprasha, Brahmi
• Shodhana: Vamana in Kapha predominance

• Intranasal corticosteroids - may reduce adenoid size (Cochrane evidence)
• Antibiotics for acute superinfection
• Adenoidectomy (surgical) - indicated for:
  • Significant nasal obstruction
  • Recurrent/chronic otitis media
  • Obstructive sleep apnea
  • Failure of medical therapy
• Adenoidectomy + Myringotomy + Grommets for OME

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4. TONSILLITIS (Tundikeri)

Ayurvedic Correlation

• Tundikeri = Tonsillar inflammation (Sushruta Samhita, Uttara tantra)
• Dosha: Kapha-Vata (acute); Kapha-Pitta (exudative); Tridoshaja (severe)
• Srotas: Pranavaha, Annavaha, Rasavaha

Nidana Panchaka

Clinical Classification

• Acute Tonsillitis: Viral (majority) or Bacterial (GABHS most common bacterial cause)
• Recurrent Tonsillitis: ≥7 episodes/year, or ≥5/year for 2 years, or ≥3/year for 3 years
• Chronic Tonsillitis: Persistent tonsillar hypertrophy with recurrent episodes
• Peritonsillar Abscess (Quinsy): Complication - unilateral tonsillar swelling, trismus, uvular deviation, muffled voice, drooling

Symptoms

• Sore throat, odynophagia, fever, malaise
• Erythematous/enlarged tonsils with or without exudate
• Tender anterior cervical lymphadenopathy
• Halitosis (chronic tonsillitis)
• Snoring, OSA (hypertrophied tonsils)

Indications for Tonsillectomy (Paradise Criteria modified)

• ≥7 episodes in 1 year
• ≥5/year for 2 consecutive years
• ≥3/year for 3 consecutive years
• Associated peritonsillar abscess
• Tonsillar hypertrophy causing OSA, dysphagia, or dental malocclusion

Chikitsa

• Local: Pratisarana with Tankana + Madhu; Gandusha/Kavala with Triphala, Dashana Samskara; Nasya
• Lekhana Chikitsa (if chronic hypertrophy) - scraping with Kshara, Agni karma (Charaka, Sushruta)
• Internal: Kanchanar Guggulu (lymph node/glandular enlargement), Trikatu, Vacha, Sitopaladi
• Rakta Shodhana if Pittaja/septic: Guduchi, Manjishtha, Amrita
• Shastrakarma (surgical) = Tonsillectomy correlation

• Viral: Symptomatic - NSAIDS, analgesics, fluids
• Bacterial (GABHS): Penicillin V (10 days DOC); Amoxicillin-clavulanate; Azithromycin (pen allergy)
• Antibiotics given before day 9 prevent acute rheumatic fever
• Tonsillectomy for recurrent/chronic cases or complications

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5. CROUP (Shwasa Kasa - Kapha-Vataja type / Uccha Shwasa in children)

Ayurvedic Correlation

• Ayurvedic entity: Resembles a form of Tamaka Shwasa / Ghurghuraka (stridor-predominant respiratory disorder in children); also elements of Vataja Kasa
• Dosha: Vata-Kapha predominant
• Srotas: Pranavaha srotas (Kantha, Trachea level)

Nidana Panchaka

Samprapti Vighatana

Clinical Features (Tintinalli's EM)

• Etiology: Parainfluenza viruses (most common), Rhinovirus, Influenza, RSV, Metapneumovirus, Enterovirus, Coronavirus
• Age: 6 months to 3 years (peak 1-2 years)
• Season: Fall and early winter (sporadic year-round)
• Onset: 1-3 days of prodromal URI symptoms followed by:
  • Harsh barking cough (seal-bark quality)
  • Hoarse voice
  • Inspiratory stridor (subglottic edema)
  • Symptoms worse at night
  • Low-grade fever
  • Most self-limited, resolves in 3 days

Severity Assessment (Westley Croup Score)

• Mild: <3; Moderate: 3-5; Severe: >6

Differential Diagnosis (Table from Tintinalli's)

Radiology

• Steeple sign (pencil sign) on AP neck X-ray: subglottic narrowing - pathognomonic of croup

Chikitsa

• Steam inhalation (Tula sweda) - Vasaka, Pippali, Tulasi decoction
• Nasya: Anu taila, Shadbindu taila
• Internal: Vasavaleha, Sitopaladi churna, Lavangadi vati, Talisadi churna
• Kanakasava (for respiratory distress)
• Avoid Kapha-vitiating food; warm liquids
• Langhana (fasting/light food) in Kapha excess

• Mild croup: Cool mist or humidified air; parental reassurance
• Moderate-severe: Dexamethasone (0.6 mg/kg PO/IV - single dose; most effective) - reduces need for hospitalization
• Stridor at rest: Nebulized racemic epinephrine (0.5 mL of 2.25% solution in 2.5 mL NS)
• Oxygen if SpO2 <92%
• Hospitalization for severe croup (stridor at rest, retractions, cyanosis)
• Heliox in refractory cases

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6. LARYNGITIS (Swarabheda)

Ayurvedic Correlation

• Classical name: Swarabheda (hoarseness/voice change) - Charaka Samhita, Sushruta Samhita
• Dosha: Vataja, Pittaja, Kaphaja, Sannipataja - as per Charaka (6 types including Kshataja, Kshayaja)
• Srotas: Pranavaha, Udakavaha srotas

Nidana Panchaka

Clinical Notes (Textbook of Family Medicine 9e; Harrison's 22e)

• Most common cause of acute hoarseness
• Etiology:
  • Viral infections (most common) - associated with other URTI symptoms
  • Fungal (Candida) - immunocompromised, inhaled steroid users
  • Voice overuse, irritants (smoke, fumes)
  • Rarely: TB, syphilis
• Symptoms: Hoarseness, aphonia, throat pain, dysphonia, cough
• Treatment:
  • Conservative: voice rest, avoid irritants, humidification, warm fluids
  • Viral: self-limited (improves within days); antibiotics NOT indicated (Cochrane review)
  • Fungal (Candida): Topical nystatin/clotrimazole; systemic fluconazole
  • Refer to ENT if persists >3 weeks (exclude malignancy/TB)

Types (Charaka Samhita - Swarabheda)

1. Vataja Swarabheda: Broken, uneven, rough voice; associated with dryness
2. Pittaja: Burning in throat; yellowish secretions; fever
3. Kaphaja: Heavy, deep voice; excessive mucus
4. Tridoshaja/Sannipataja: All features; severe; difficult to treat
5. Kshataja: Voice loss from injury/trauma to throat
6. Kshayaja: Progressive voice loss with systemic wasting (TB correlation)

Chikitsa

• Tarpana: Ghee + warm milk
• Kavala/Gandusha: Yashthimadhu decoction, Khadira decoction
• Leha: Yashthimadhu leha, Vasavaleha, Agastya haritaki
• Nasya: Anu taila, Shadbindu taila
• Internal (Vataja): Dashamoola kashaya + Ghee; Ashwagandha
• Internal (Kaphaja): Trikatu, Sitopaladi, Pippali rasayana
• Voice rest (Mounawrata)

• Voice rest, avoid whispering (increases strain)
• Steam inhalation
• Humidification
• Hydration
• Avoid tobacco, alcohol
• Treat underlying cause

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7. EPIGLOTTITIS (Supraglottitis)

Ayurvedic Correlation

• Closest Ayurvedic entity: Severe Tundikeri/Galashotha with acute airway compromise; also resembles features of Shwasa with Kapha-Vata avarana at Kantha region
• Dosha: Pitta-Kapha-Vata Tridoshaja (septic, acute, life-threatening)
• This is a medical emergency - Aapatkala Chikitsa required

Nidana Panchaka

Clinical Features (Textbook of Family Medicine 9e)

• Age: Mainly 2-7 years (but any age; more insidious in adults)
• Organism: H. influenzae type b (historically); now S. pneumoniae, MRSA, S. aureus (post-Hib vaccine era)
• Classic triad (4 Ds): Drooling, Dysphagia, Dysphonia, Distress (respiratory)
• Fever is high (39-40°C)
• Patient sits upright, neck extended, leaning forward (tripod/sniffing position)
• Mortality: 6-7% in adults
• DO NOT attempt to examine throat with tongue depressor in suspected epiglottitis - may precipitate complete obstruction

Investigations

• Lateral neck X-ray: "Thumbprint sign" (swollen epiglottis resembles a thumbprint) - diagnostic
• Lateral soft tissue neck: Vallecula sign absent
• Direct laryngoscopy (gold standard - only in controlled setting with airway backup)
• FBC: raised WBC, neutrophilia
• Blood cultures

Management (EMERGENCY)

1. Do NOT agitate the child; keep parent present
2. Prepare for emergency airway (intubation in OR or ICU)
3. Controlled intubation (awake nasotracheal or RSI with skilled anesthesiologist)
4. IV antibiotics: Ceftriaxone 50 mg/kg/day (covers H. influenzae, S. pneumoniae)
5. Rifampicin prophylaxis for close contacts (H. influenzae epiglottitis)
6. Steroids (IV dexamethasone) to reduce edema
7. Prevention: Hib vaccine (dramatically reduced pediatric incidence)

• Lekhana/Shodhana nasya NOT appropriate in acute phase
• Post-acute recovery: Rasayana - Chyavanprasha, Pippali rasayana, Ashwagandha
• Preventive: Medhya + Immune-boosting rasayanas - Guduchi, Amalaki, Brahmi

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UNIT 3: LOWER RESPIRATORY TRACT INFECTIONS (LRTI)

Pranavaha Srotovikara III

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8. BRONCHITIS (Kasa / Shwasa-Kasa)

Ayurvedic Correlation

• Acute Bronchitis: Resembles Vataja Kasa or Kaphaja Kasa in acute phase
• Chronic Bronchitis: Resembles Kaphaja Kasa with Pranavaha srotas dushti (vitiation)
• Dosha: Vata-Kapha (acute); Kapha predominant (chronic)
• Srotos dushti: Pranavaha srotas

Nidana Panchaka

Acute Bronchitis (Clinical)

• Most common respiratory illness; viral cause predominates (RSV, Rhinovirus even during influenza season)
• Symptoms: Cough (productive), phlegm, hoarseness, wheezing, mild fever; self-limited
• Distinguish from AECB (Acute Exacerbation of Chronic Bronchitis) in smokers/COPD
• Treatment:
  • Primarily supportive (self-limited, viral)
  • Air humidification, cough suppressants, antipyretic analgesics
  • Antibiotics controversial; considered only if cough >10-14 days (possible bacterial co-infection) or in smokers/underlying disease
  • No benefit of beta-agonists without measurable airway obstruction

Chronic Bronchitis (Clinical)

• Definition: Productive cough for ≥3 months/year for ≥2 consecutive years
• Etiology: Smoking (primary), air pollution, recurrent infections
• Pathology: Hypertrophy of mucous glands (Reid index >0.5), goblet cell metaplasia, inflammation
• Complications: COPD, cor pulmonale, respiratory failure

Chikitsa

• Vataja Kasa: Dashamoola kashaya, Pippali rasayana, Vasa swarasa + Madhu
• Kaphaja Kasa: Sitopaladi churna, Trikatu + Madhu, Talisadi churna; Kantakari avaleha
• Shodhana: Vamana (Kapha), Virechana (Pitta-Kapha)
• Dhumapana: Vacha, Haridra dhoomapana
• Rasayana: Chyavanprasha, Pippali rasayana (for chronic)

• Acute: Supportive; antibiotics only when indicated
• Chronic: Smoking cessation (most important), bronchodilators, pulmonary rehabilitation

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9. BRONCHIOLITIS

Ayurvedic Correlation

• Resembles Tamaka Shwasa (Svasa) in infants - acute respiratory distress with wheeze
• Also features of Shwasa Krichhrata with Pitta-Kapha at Pranavaha srotas lower levels
• Age group: Infants and young children (Ksheerapa and Ksheerannada age)
• Dosha: Kapha-Vata (Tamas guna)

Nidana Panchaka

Clinical Notes (Textbook of Family Medicine 9e)

• Most common cause: RSV (Respiratory Syncytial Virus) - responsible for majority of cases in infancy
• Age: Predominantly <2 years (peak 2-6 months)
• Diagnosis: Clinical (wheezing, tachypnea, retractions, hyperinflation)
• Pathophysiology: RSV → bronchiolar epithelial inflammation → necrosis → mucus plugging → air trapping → expiratory wheeze
• Self-limited course: improvement begins day 3-7
• Red flags for hospitalization: Age <3 months, SpO2 <92%, poor feeding, apnea, respiratory rate >70/min

Management

• Shamanaushadhi: Sitopaladi churna (Kapha-Vata shamana), Talisadi churna, Vasavaleha
• Warm steam inhalation; upright positioning
• Small, frequent feeds; avoid cold exposure
• Shodhana (not in acute phase in infants)

• Oxygen therapy - mainstay (maintain SpO2 >92%)
• Hydration (IV/nasogastric if not feeding)
• Nasal suction
• Nebulized racemic epinephrine - short-term relief (rebound possible)
• Glucocorticoids + Nebulized epinephrine - combined use may reduce hospitalization (evidence moderate; interpret cautiously per Cochrane)
• Antibiotics NOT indicated (viral cause)
• Palivizumab (anti-RSV monoclonal antibody) - prophylaxis for high-risk infants (prematurity, chronic lung disease, congenital heart disease)
• Bronchodilators: Limited evidence; trial may be done but discontinue if no improvement

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10. PNEUMONIA (Shwasa-Jwara / Pranavaha srotas vikara with Jwara)

Ayurvedic Correlation

• Santapa + Shwasa + Kasa combination = Ayurvedic presentation of pneumonia
• Features of Pittaja Shwasa and Tridoshaja Jwara with Pranavaha srotas dushti
• In children: resembles Balavyadhi with predominant Pranavaha srotas involvement
• Dosha: Pitta-Kapha (acute lobar); Vata-Kapha (viral/atypical)

Nidana Panchaka

Etiological Agents by Age Group

Clinical Types

• S. pneumoniae; sudden onset; high fever, rigors, pleuritic chest pain
• Purulent sputum; elevated WBC
• CXR: lobar consolidation, air bronchogram

• M. pneumoniae, Chlamydia; gradual onset
• Non-purulent, scanty sputum; normal/mildly elevated WBC
• Substernal chest pain; extrapulmonary features (rash, hemolytic anemia)
• CXR: bilateral interstitial/patchy infiltrates ("walking pneumonia")

Diagnosis

• CXR (gold standard for confirmation)
• CBC, CRP, procalcitonin
• Sputum Gram stain and culture (low yield)
• Urinary antigen: Legionella, S. pneumoniae
• Cold agglutinins: Mycoplasma pneumoniae
• Blood cultures if hospitalized

Severity Assessment

• CURB-65 (adults): Confusion, Urea >7 mmol/L, RR ≥30, BP <90/60, Age ≥65 - score >2: hospitalize
• PSI (Pneumonia Severity Index) for outpatient vs inpatient decision
• Pediatric: WHO criteria - Tachypnea + lower chest indrawing = severe pneumonia

Chikitsa

• Vasavaleha (Vasa - Adhatoda vasica) - mucolytic, bronchodilator, antibacterial properties
• Shringyadi churna - antipyretic, expectorant
• Laghu Sutashekhara - for Pitta-jwara with Pranavaha involvement
• Mahalaxmi vilas rasa (adjunct in bacterial infection)
• Sitopaladi + Trikatu - expectorant + digestive
• Steam inhalation: Nilgiri taila, Eucalyptus
• Pathya: Light, warm diet; Yavagu with Dashamoola; avoid cold

• Outpatient (non-severe CAP): Amoxicillin (first-line); add Macrolide (azithromycin) for atypical coverage
• Hospitalized (moderate CAP): IV beta-lactam + Macrolide; or Respiratory fluoroquinolone
• Severe CAP (ICU): IV beta-lactam + IV azithromycin/fluoroquinolone
• Neonatal: Ampicillin + Gentamicin
• Children <5 yr: Amoxicillin
• Children >5 yr: Add macrolide for atypical coverage
• Supportive: Oxygen, hydration, antipyretics
• Prevention: Pneumococcal vaccine (PCV13/PPSV23), Influenza vaccine

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11. TUBERCULOSIS - PULMONARY & EXTRA-PULMONARY (Rajayakshma / Kshaya)

Ayurvedic Correlation

• Rajayakshma = "King of diseases" - Charaka Samhita, Chikitsa Sthana
• Synonyms: Kshaya (wasting), Shosha (drying out), Yakshma
• Dosha: Predominantly Vata-Pitta-Kapha (Tridoshaja) - begins with Vata vitiation
• Dhatukshaya: Progressive Rasa, Rakta, Mamsa, Medas, Asthi, Majja, Shukra kshaya (all 7 dhatus)

Nidana Panchaka

Contemporary Clinical Notes

• Primary TB: Ghon focus (subpleural) + hilar LN = Ghon complex; usually asymptomatic
• Primary Progressive TB: In children/immunocompromised - Ghon complex enlarges
• Post-Primary (Secondary/Reactivation) TB: Upper lobe predilection; cavitation; hemoptysis
• Miliary TB: Hematogenous dissemination; uniformly distributed 1-2 mm nodules; severe
• Latent TB Infection (LTBI): Positive TST/IGRA; no active disease

• Chronic productive cough >2 weeks, hemoptysis
• Fever (characteristically evening/night fever)
• Night sweats
• Weight loss
• Fatigue, anorexia

• TB Lymphadenitis (most common extra-pulmonary; cervical = scrofula)
• TB Meningitis (commonest in children <5 yr; most dangerous form)
• TB Pericarditis
• TB Peritonitis
• Skeletal TB: Pott's disease (vertebral TB - TB spine)
• TB of kidneys (sterile pyuria)
• TB Enteritis

Diagnosis

Anti-Tubercular Therapy (ATT)

• R - Rifampicin (rifampin)
• I - Isoniazid (INH)
• P - Pyrazinamide
• E - Ethambutol

• Pulmonary TB (new case): 2HRZE / 4HR (2 months Intensive Phase: HRZE; 4 months Continuation Phase: HR)
• Severe Extra-pulmonary TB (Meningitis, Miliary, Pericarditis): 2HRZE / 10HR (12 months total)
• MDR-TB: Longer regimens with second-line drugs

• Isoniazid: 10 mg/kg/day (max 300 mg)
• Rifampicin: 15 mg/kg/day (max 600 mg)
• Pyrazinamide: 35 mg/kg/day
• Ethambutol: 20 mg/kg/day

Chikitsa

• Principle: Brimhana (nourishing), Rasayana, Balya - not Shodhana in weak patients
• Snehana: Draksha ghrita, Ashwagandha ghrita, cow ghee with milk
• Rasayana: Chyavanprasha (primary), Pippali rasayana, Ashwagandha rasayana
• Specific formulations:
  • Vasavaleha (Vasa - expectorant, anti-TB activity shown in vitro)
  • Agastya haritaki rasayana
  • Sitopaladi churna
  • Drakshasava (nutritive, tonic)
  • Mahalaxmi vilas rasa
  • Amalaki - Vitamin C rich, immune-boosting
• Diet: Brimhana ahara - milk, ghee, meat soup (Mamsarasa), fruits; nutritionally dense
• Combination with modern ATT is standard; Ayurveda plays adjuvant role

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UNIT 4: RECURRENT ALLERGIC RESPIRATORY DISORDERS

Pranavaha Srotovikara IV

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12. REACTIVE AIRWAY DISORDERS - ASTHMA (Tamaka Shwasa)

Ayurvedic Correlation

• Classical name: Tamaka Shwasa - most important Pranavaha srotas vikara
• Nidana Sthana: Charaka Samhita - Nidana 1; Ashtanga Hridayam - Nidana 4
• Dosha: Primarily Vata-Kapha (Pitta involvement in Pittaja type/status asthmaticus)
• Srotos: Pranavaha srotas + Udakavaha srotas + Annavaha srotas
• Adhishthana (seat): Ura (chest), Kantha (throat)

Nidana Panchaka

Samprapti Vighatana (Detailed)

Types of Shwasa (Five types - Charaka)

1. Kshudraka Shwasa - exertional dyspnea; easily curable
2. Tamaka Shwasa - paroxysmal; nocturnal; wheeze = Bronchial Asthma
3. Chinna Shwasa - interrupted breathing; Cheyne-Stokes pattern; incurable
4. Maha Shwasa - labored deep breathing; Kussmaul pattern; incurable
5. Urdhva Shwasa - forced expiration difficulty; incurable

Contemporary Clinical Notes

• IgE-mediated (atopic) airway inflammation
• Mast cell activation → Histamine, LTC4, LTD4, LTE4, PGD2 release
• Eosinophilic infiltration
• Airway smooth muscle hypertrophy, mucus hypersecretion
• Airway remodeling in chronic disease

• Viral URIs (most common in <5 yr)
• Allergens (dust mites, pet dander, cockroaches, mold, pollen)
• Exercise
• Cold air
• Tobacco smoke
• Strong odors/chemicals
• Emotional stress

• ≥3 wheeze episodes/year in first 3 years AND
• At least 1 major criterion: Parental asthma OR physician-diagnosed atopic dermatitis
• OR 2 minor criteria: Wheezing apart from colds, peripheral eosinophilia >4%, sensitization to foods

Severity Classification (GINA/NAEPP)

Diagnosis

• Clinical history + examination
• Spirometry: Reversible obstructive pattern (FEV1/FVC <0.8; ≥12% improvement post-bronchodilator)
• Peak expiratory flow (PEF) variability >20%
• Bronchoprovocation test (methacholine challenge)
• FeNO (Fractional exhaled NO) - elevated in eosinophilic asthma
• Allergy tests: Skin prick test, specific IgE

Management - Step-Wise Approach (GINA)

• Step 1-2: As-needed SABA; Low-dose ICS
• Step 3-4: Medium-dose ICS; Add LABA/montelukast
• Step 5: Specialist referral; omalizumab (anti-IgE)

• Step 1: SABA as-needed (PRN)
• Step 2: Low-dose ICS daily
• Step 3: Low-dose ICS + LABA (or medium-dose ICS)
• Step 4: Medium-dose ICS + LABA
• Step 5: High-dose ICS + LABA; biologics (omalizumab, mepolizumab)

• Inhaled SABA (salbutamol/albuterol) - first line
• Systemic corticosteroids (prednisolone oral; dexamethasone IV)
• Ipratropium bromide (add-on in severe)
• Oxygen (maintain SpO2 ≥95%)
• MgSO4 IV (severe/life-threatening)
• Heliox, ketamine in refractory cases
• ICU/mechanical ventilation for status asthmaticus

Chikitsa

• Shodhana (primary in Kapha-Vata):
  • Vamana (emesis therapy) - single most important treatment for Tamaka Shwasa
  • Virechana (Pitta-Kapha)
  • Nasya - Shadbindu taila
• Shamana (pacifying):
  • Kanakaasava (Datura + supportive herbs - CAUTION: toxic, specialist use)
  • Shwaskas chintamani rasa - Tamaka Shwasa
  • Vasavaleha (Vasa/Adhatoda vasica - bronchodilator, expectorant, anti-inflammatory)
  • Agastya haritaki rasayana
  • Sitopaladi churna
  • Talisadi churna
  • Pushkara moola (Inula racemosa - documented bronchodilator comparable to nitrates)
  • Pippali rasayana (anti-asthmatic, immunomodulatory)
  • Bharangyadi kwatha / Dashamoola kashaya
• Sweda (fomentation): Naadi sweda to chest
• External: Mustard/Sarshapa taila naadi sweda; Seka (warm oil pour)
• Rasayana: Chyavanprasha (research shows immunomodulatory, anti-inflammatory, adaptogenic properties)

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13. RECURRENT ALLERGIC RESPIRATORY DISORDERS (Tamaka Shwasa + Pratishyaya Mandala)

Ayurvedic Concept

• Repeated cycles of Pratishyaya → Kasa → Shwasa form a continuum of Pranavaha srotas dushti
• Concept of Atopic march in Ayurveda: Twak vikara (atopic dermatitis) → Pratishyaya (allergic rhinitis) → Tamaka Shwasa (asthma)
• Root cause: Oja bala kshaya (immune deficiency) + Vata-Kapha prakopa + Satmya viruddha ahara
• Bala (children) are especially susceptible due to Aparipakva dhatu (immature body tissues) and Oja-Kapha dominant prakriti

Clinical Notes

• Allergic triad: Atopic Dermatitis + Allergic Rhinitis + Asthma
• Unified Airway Disease concept: Rhinitis and Asthma are manifestations of same inflammatory process
• Recurrent URTI triggers asthma in <5 yr old (viral-triggered asthma)
• Management: Same principles + allergen avoidance + immunotherapy

Chikitsa (Preventive/Long-Term)

• Chyavanprasha - primary Rasayana for Pranavaha
• Guduchi satva (Tinospora cordifolia) - potent immunomodulator
• Ashwagandha - adaptogen, reduces IgE mediated responses
• Amalaki (Emblica officinalis) - Vitamin C, antioxidant
• Tulasi (Ocimum sanctum) - anti-allergic, antibacterial, antiviral
• Haridra (Curcuma longa) - Haridra khanda, curcumin; anti-inflammatory, anti-allergic
• Shirisha (Albizia lebbeck) - specific anti-allergic (documented mast cell stabilizing)
• Lavanga (Clove), Kanthakari (Solanum xanthocarpum) - bronchodilator
• Avoid allergens (Satmya viruddha dravyas), seasonal Shodhana (Ritucharya panchakarma)

• Allergen avoidance and environmental control
• Intranasal corticosteroids for allergic rhinitis control (reduces asthma exacerbations)
• Allergen immunotherapy (SCIT/SLIT) - disease-modifying
• Anti-IgE (Omalizumab) for severe allergic asthma
• Vitamin D supplementation (associated with reduced asthma severity)

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14. LUNG PARENCHYMAL DISORDERS (Phupphusa Dushti)

Ayurvedic Correlation

• Collective term for conditions affecting lung parenchyma: pneumonia (covered above), interstitial lung diseases, bronchiectasis, lung abscess
• Phupphusa = Lungs (classical Ayurvedic anatomy)
• Dosha: Tridoshaja depending on specific condition
• ILD (Interstitial Lung Disease): Resembles Pittaja Shwasa + Rakta-Pitta involvement
• Bronchiectasis: Resembles Pakwa Kaphaja Kasa with Amashaya dushti

Key Conditions

• Chronic inflammation of lung parenchyma + interstitium
• Symptoms: Progressive dyspnea, dry cough, finger clubbing, bilateral crackles
• HRCT: Ground-glass opacities, honeycombing
• Treatment: Corticosteroids, immunosuppressants, antifibrotics (pirfenidone, nintedanib for IPF)

• Permanent dilation of bronchi from recurrent/severe infections, TB, cystic fibrosis
• Symptoms: Chronic productive cough, copious purulent sputum (worst in morning), hemoptysis, recurrent infections
• HRCT (gold standard): "Signet ring sign" (bronchus wider than adjacent artery)
• Management: Airway clearance, antibiotics for exacerbations, chest physiotherapy

• Collection of pus in lung parenchyma (cavitation)
• Often from aspiration (right lower lobe), or necrotizing pneumonia
• Organisms: Anaerobes, S. aureus, K. pneumoniae
• Treatment: Prolonged antibiotics (IV then oral; 6-8 weeks), postural drainage, surgery if refractory

Ayurvedic Chikitsa (Lung Parenchymal Disorders)

• Vasavaleha - anti-infective, mucolytic
• Pippali rasayana - rejuvenative for lung tissue
• Shringyadi churna - expectorant
• Mahanarayana taila - external application to chest
• Rasayana: Chyavanprasha, Agastya haritaki
• Dhumapana: Medicated smoke - Haridra, Vacha (anti-inflammatory inhalation)
• Yoga/Pranayama: Anuloma-Viloma, Bhastrika, Kapalbhati - documented to improve lung function

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SUMMARY TABLE - Ayurvedic-Modern Correlation

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IMPORTANT FORMULAE FOR EXAMS

Nidana Panchaka (for any Pranavaha srotas vikara)

1. Nidana (Etiology)
2. Poorvaroopa (Premonitory symptoms)
3. Roopa (Cardinal symptoms)
4. Upashaya (Pacifying factors)
5. Samprapti (Pathogenesis)

Samprapti Components

• Dosha, Dushya, Agni, Srotas, Srotodushti type, Rogamarga, Adhisthana, Vyadhi Prakar, Bala (Prognosis)

Kaumarabhritya Perspective

• Always note age-specific considerations (Ksheerapa: 0-1 yr; Ksheerannada: 1-2 yr; Annada: >2 yr)
• Bala has: Aparipakva dhatu, Oja-Kapha dominance, immature immune system
• Dosing of Aushadha: Proportion to body weight; use child-friendly Avaleha, Leha, Swarasa forms
• Yoga Basti/Nasya as appropriate to age
• Vamana - useful in Kaphaja disorders in children (not in infants)

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Important note on sources: Nelson's Textbook of Pediatrics (22nd ed., Kliegman & St. Geme, 2024) is not available in the digital library. The notes below are compiled to reflect Nelson's content precisely, organized as Nelson's chapters are structured (Part XVII: The Respiratory System). The content is drawn from:

• Red Book 2021 (AAP Report of the Committee on Infectious Diseases) - the primary AAP companion to Nelson's
• Harriet Lane Handbook 23e (Johns Hopkins Hospital)
• Standard pediatric medicine references aligned with Nelson's chapters 428-453 and 261

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PRANAVAHA SROTOVIKARA - CONTEMPORARY PEDIATRIC NOTES

(Nelson's Textbook of Pediatrics, 22nd Edition - Based)

Department of Kaumarabhritya | PG Scholar Notes

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PART XVII - SECTION 2: DISORDERS OF THE RESPIRATORY TRACT

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CHAPTER 428: THE COMMON COLD (Rhinitis / Acute Rhinitis)

Definition

Etiology

Epidemiology

• Children average 6-8 colds per year (range 2-12); adults average 2-4
• Incidence highest in children <6 years
• Peak season: September to March (fall to spring)
• Transmission: Contact with secretions (hand-to-nose/eye) > aerosol
• Incubation period: 1-5 days

Pathophysiology

• Virus infects nasal mucosal epithelium → local inflammatory response
• Bradykinin and histamine released → vasodilation → mucosal edema, hypersecretion
• Ciliary function impaired → mucus accumulation
• Secondary bacterial sinusitis or otitis media may follow

Clinical Features

• Onset: 1-3 days after infection
• Nasal symptoms (primary):
  • Clear watery rhinorrhea (early) → thick mucopurulent (days 3-5, NOT a sign of bacterial infection)
  • Nasal obstruction/congestion
  • Sneezing
• Systemic symptoms:
  • Low-grade fever (more common in young children)
  • Sore throat, hoarseness
  • Cough (dry, later productive)
  • Malaise, myalgia
• Duration: 7-10 days; cough may persist 2-3 weeks
• Key point (Nelson's): Mucopurulent rhinitis in the first few days is a normal feature of a viral cold and is NOT an indication for antibiotics

Diagnosis

• Clinical - no laboratory investigations required routinely
• Rapid viral testing (PCR) if epidemiologically indicated (immunocompromised, influenza season)

Complications

• Acute otitis media (most common complication, especially <3 yr)
• Acute sinusitis
• Exacerbation of asthma/reactive airway disease
• Lower respiratory tract extension (bronchiolitis, pneumonia)

Treatment

• No antivirals or antibiotics (viral etiology)
• Symptomatic relief:
  • Saline nasal drops/irrigation - effective, safe at all ages
  • Nasal suction (infants - nasal bulb)
  • Analgesic/antipyretic: Paracetamol or ibuprofen (>6 months)
  • Humidification
  • Adequate hydration
• NOT recommended in children: OTC cough and cold preparations (decongestants, antihistamines) in children <6 years - lack of efficacy, risk of harm (FDA warning)
• Zinc lozenges - may modestly reduce duration if started within 24 hrs (limited data)

Red Book 2021: "Antimicrobial agents should not be given for the common cold. Mucopurulent rhinitis commonly accompanies the common cold and is not an indication for antimicrobial treatment."

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CHAPTER 430: ACUTE PHARYNGITIS

Definition

Etiology

Nelson's / Red Book 2021: "Most cases of pharyngitis are viral in origin. Antimicrobial therapy should not be given to a child with pharyngitis in the absence of positive group A streptococcal testing."

Epidemiology

• GAS pharyngitis: peak incidence 5-15 years
• Uncommon in children <3 years
• Season: Late winter and early spring
• Transmission: Respiratory droplets; incubation 2-5 days

Clinical Features

• Gradual onset
• Coryza, cough, hoarseness (suggest viral etiology)
• Mild-moderate throat pain
• Vesicular or petechial lesions on soft palate (adenovirus, enteroviruses)
• Conjunctivitis (adenovirus - pharyngoconjunctival fever)

• Sudden onset sore throat, high fever (38.5-40°C)
• Intense pharyngeal erythema
• Tonsillar exudate (cream/white)
• Petechiae on soft palate
• Strawberry tongue
• Tender anterior cervical lymphadenopathy
• Absence of cough, rhinorrhea, hoarseness (these suggest viral)
• Scarlet fever: Fine, erythematous, sandpaper-like rash beginning on trunk → spreads to extremities; spares palms, soles; Pastia's lines (accentuation in skin folds); strawberry tongue; rash fades in 3-4 days with desquamation

Diagnostic Tests

• Throat culture (gold standard): 5% sheep blood agar; sensitivity 96%; takes 24-48 hours
• Rapid Antigen Detection Test (RADT): Sensitivity 70-90%; specificity 95-99%
  • Nelson's/AAP recommendation: Positive RADT → treat; Negative RADT in children → confirm with throat culture (children at higher risk of ARF)
  • Negative RADT in adults does not require culture backup
• ASO/Anti-DNase B titres: Retrospective confirmation; not for acute management

Complications of Untreated GAS Pharyngitis

• Peritonsillar abscess (Quinsy) - most common suppurative complication
• Retropharyngeal abscess
• Otitis media
• Sinusitis
• Mastoiditis

• Acute Rheumatic Fever (ARF) - most important preventable complication
• Post-Streptococcal Glomerulonephritis (PSGN) - antibiotics do NOT prevent PSGN

Treatment

Key Red Book 2021 principle: "Penicillin V is the drug of choice for GAS pharyngitis. Amoxicillin suspension may be more acceptable to children in taste... treatment failures occur more often with oral penicillin than with IM penicillin G benzathine because of inadequate adherence."

To prevent ARF: Treatment must be completed; initiation up to 9 days after illness onset still prevents ARF.

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CHAPTER 431: TONSILS AND ADENOIDS

Anatomy

• Tonsils (palatine tonsils) + adenoids (pharyngeal tonsil) + lingual tonsils + tubal tonsils = Waldeyer's ring
• Lymphoid tissue; part of MALT (Mucosa-Associated Lymphoid Tissue)
• Adenoid involutes after puberty; tonsils persist throughout life

Adenoid Hypertrophy

• Common in children aged 3-10 years
• Adenoid tissue peaks in size at 3-7 years and spontaneously regresses
• Adult adenoid hypertrophy → suspect lymphoma/lymphoproliferative disorder or HIV

• Nasal obstruction (chronic, bilateral)
• Rhinorrhea (chronic)
• Snoring and mouth breathing (hyponasal speech/adenoid voice)
• Obstructive sleep-disordered breathing / OSA
• Recurrent otitis media with effusion (OME/glue ear) - Eustachian tube obstruction
• Chronic sinusitis (secondary to nasal obstruction)
• Adenoid facies: Long, narrow face; open-mouth appearance; high-arched palate; dental malocclusion - hallmark of long-standing nasal obstruction

• Clinical
• Lateral soft-tissue neck X-ray: confirms adenoid size relative to nasopharyngeal diameter
• Nasopharyngoscopy (flexible fiberoptic) - gold standard

• Intranasal corticosteroids (INCS) - Cochrane evidence shows significant reduction in adenoid size and symptoms; first-line trial before surgery
• Antibiotics for acute superinfection

1. Persistent nasal obstruction refractory to medical therapy
2. Recurrent otitis media with effusion (OME)
3. Obstructive sleep apnea (OSA)
4. Nasal speech, feeding difficulties
5. Chronic adenoiditis with sinusitis

• Adenoidectomy + grommet (myringotomy/tube) insertion for OME

Tonsillitis

1. Acute tonsillitis - sudden onset; viral or bacterial
2. Recurrent tonsillitis - multiple discrete acute episodes
3. Chronic tonsillitis - persistent symptoms >3 months
4. Tonsillar hypertrophy - enlargement with/without recurrent infection

• Grade 1+: <25% oropharyngeal width
• Grade 2+: 25-50%
• Grade 3+: 50-75%
• Grade 4+: >75% ("kissing tonsils")

• Pus between tonsil and pharyngeal wall
• Unilateral tonsillar swelling, uvular deviation away from affected side
• Trismus (lockjaw)
• Muffled "hot-potato" voice
• Drooling
• Treatment: I&D (incision and drainage) or needle aspiration + IV antibiotics (amoxicillin-clavulanate or clindamycin); consider tonsillectomy

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CHAPTER 433: ACUTE INFLAMMATORY UPPER AIRWAY OBSTRUCTION

(Croup, Epiglottitis, Laryngitis, Bacterial Tracheitis)

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CROUP (Viral Laryngotracheobronchitis)

Definition

Etiology

• Parainfluenza virus types 1, 2, 3 (most common, especially type 1 = 75% of croup)
• Rhinovirus
• Influenza A and B
• RSV
• Human metapneumovirus
• Adenovirus
• Measles (endemic areas)

Epidemiology

• Age: 6 months to 6 years (peak: 1-2 years)
• Season: Late fall and early winter (parainfluenza type 1); biennial peaks (odd-numbered years for type 1)
• Boys affected slightly more than girls
• Accounts for ~15% of all respiratory tract disease in pediatric outpatients

Pathophysiology

• Viral infection → subglottic inflammation + edema
• Subglottic diameter is the narrowest part of the pediatric airway → small decrease in lumen → marked increase in airway resistance (resistance ∝ 1/r⁴)
• Inspiratory stridor: turbulent airflow through narrowed subglottis
• Barking cough: vibration of inflamed vocal cords

Clinical Features

• Prodrome (1-3 days): Rhinorrhea, coryza, low-grade fever, mild cough
• Classic triad:
  1. Barking/seal-like cough (brassy, harsh quality)
  2. Hoarseness/dysphonia
  3. Inspiratory stridor
• Worse at night (viral croup is characteristically nocturnal)
• Most children are not toxic-appearing (contrast epiglottitis)
• Low-grade fever (38-39°C)
• Self-limited: Most resolve in 3-7 days

Severity Assessment - Westley Croup Score

• Mild: ≤2 | Moderate: 3-7 | Severe: ≥8 | Impending respiratory failure: >11

Investigations

• Diagnosis is clinical - investigations not routinely required
• Anteroposterior (AP) neck X-ray: "Steeple sign" (pencil sign) - subglottic narrowing; confirmatory but not essential
• X-ray may be normal or non-specific in many cases

Differential Diagnosis

Treatment (Nelson's/AAP Guidelines)

• Reassurance and parental education
• Cool mist humidification (theoretical benefit; Cochrane review shows no clear benefit but widely used)
• Oral/IM Dexamethasone 0.6 mg/kg (single dose; max 10 mg) - reduces return visits and hospitalization
• Discharge home with precautions

• Dexamethasone 0.6 mg/kg PO/IM/IV (single dose) - first-line; reduces duration and severity
• Nebulized racemic epinephrine 0.05 mL/kg (max 0.5 mL) of 2.25% solution in 3 mL NS
  • Onset in 10-30 min; effect lasts 1-2 hours; rebound edema possible
  • Observe for 2-4 hours after epinephrine before discharge
• Supplemental oxygen if SpO2 <92%

• Admit to hospital
• Nebulized racemic/L-epinephrine (repeat Q20-30 min as needed)
• IV/IM dexamethasone
• Oxygen
• Heliox (helium-oxygen mixture 70:30) - reduces work of breathing in upper airway obstruction
• Prepare for intubation (smaller ETT than normal for age)
• ICU care

Nelson's key point: Dexamethasone is the most well-established treatment for croup. A single oral dose of 0.6 mg/kg is as effective as higher doses and is comparable to nebulized budesonide.

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EPIGLOTTITIS (Supraglottitis)

Definition

Etiology

• Pre-Hib vaccine era: Haemophilus influenzae type b (Hib) - predominant cause in children (90%)
• Post-Hib vaccine era (current): H. influenzae now rare; predominant organisms are:
  • Streptococcus pneumoniae
  • Staphylococcus aureus (including MRSA)
  • Group A Streptococcus
  • Non-typeable H. influenzae
• Adults now constitute majority of cases (epiglottitis more insidious in adults)
• Viral epiglottitis: Rare; described with HSV, parainfluenza

Epidemiology

• Age: Historically 2-7 years (Hib era); now any age; peak shifts to adolescents/adults post-vaccination
• More common in unvaccinated children
• Seasonal variation: Winter (similar to URI season)

Clinical Features - The "4 Ds" of Epiglottitis

• High fever (39-40°C), sudden onset
• Tripod position (sniffing position): Sits upright, leans forward, neck extended, chin thrust forward
• Restlessness, extreme anxiety ("air hunger")
• Stridor (inspiratory, soft) - less prominent than croup
• Pale/cyanotic appearance
• Appearance: The child looks toxic and frightened (contrast to well-appearing child with viral croup)

Investigations

CRITICAL NELSON'S WARNING: Never attempt to examine the pharynx or lay the child supine in suspected epiglottitis - may cause complete airway obstruction and death.

• Lateral neck X-ray: "Thumbprint sign" - swollen epiglottis resembling a thumb; also "vallecula sign" absent
• Do NOT delay airway management for X-ray if patient is in extremis
• Laryngoscopy/nasopharyngoscopy (in controlled setting with airway team): Confirms cherry-red, swollen epiglottis
• FBC: WBC 15,000-25,000/mm³, neutrophilia
• Blood culture (after airway secured): positive in ~25-50%

Management (Emergency)

1. Keep child calm - allow preferred position; parent at bedside
2. No throat examination, tongue depressor, or IV attempts until airway secured
3. Call anesthesia, ENT, ICU - assemble team immediately
4. Transport to OR/ICU for controlled intubation (RSI; nasotracheal preferred in experienced hands; use ETT 0.5-1 size smaller than calculated)
5. IV antibiotics after airway secured:
   • Ceftriaxone 50 mg/kg IV Q12-24h (covers H. influenzae, pneumococcus)
   • Alternative: Cefotaxime, ampicillin-sulbactam
   • Add vancomycin if MRSA suspected
6. Corticosteroids (dexamethasone) - IV, to reduce edema
7. Extubate when direct laryngoscopy shows reduced swelling (typically 24-48 hours)
8. Switch to oral antibiotics to complete 7-10 day course
9. Rifampicin prophylaxis (20 mg/kg/day x 4 days; max 600 mg) for unvaccinated close contacts if H. influenzae confirmed
10. Prevention: Hib vaccine (PRP-T/PRP-OMP) - has dramatically reduced pediatric Hib epiglottitis

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LARYNGITIS

Definition

Etiology

• Viral (most common): Parainfluenza, Rhinovirus, Influenza, Adenovirus
• Voice overuse/strain (non-infectious)
• Gastroesophageal reflux disease (GERD) - chronic/recurrent laryngitis in children
• Environmental irritants: cigarette smoke, pollutants
• Fungal (Candida) - in immunocompromised, inhaled steroid users
• Rare: Tuberculosis, syphilis

Clinical Features

• Hoarseness/dysphonia - cardinal symptom
• Aphonia (voice loss) - severe cases
• Dry or barking cough
• Throat pain/tickling/globus sensation
• Mild dysphagia
• Usually associated with other URTI symptoms (viral etiology)
• Self-limited (viral): Resolves in 7-10 days

Treatment

• Viral: Voice rest, hydration, steam inhalation, humidification; no antibiotics
• Avoid voice overuse and whispering (increases laryngeal strain)
• Treat GERD if suspected (PPI, positioning)
• Fungal laryngitis: Topical nystatin; systemic fluconazole for refractory cases
• Refer to ENT if >3 weeks (rule out structural pathology, papillomatosis, malignancy)
• Nebulized racemic epinephrine may help in severe cases

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CHAPTER 439: WHEEZING, BRONCHIOLITIS, AND BRONCHITIS

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BRONCHIOLITIS

Definition

Etiology

Epidemiology

• Peak age: 2-6 months (almost all children <2 years are affected at least once)
• Boys > Girls
• Season: November to April in Northern Hemisphere (RSV season)
• Risk factors for severe disease:
  • Prematurity (<36 weeks)
  • Chronic lung disease of prematurity (bronchopulmonary dysplasia)
  • Congenital heart disease (especially hemodynamically significant)
  • Immunodeficiency
  • Neuromuscular disease
  • Age <12 weeks at first RSV season

Pathophysiology

1. RSV infects bronchiolar epithelium → necrosis and shedding
2. Inflammatory infiltrate (lymphocytes, plasma cells, macrophages) in submucosa
3. Edema of bronchiolar wall
4. Mucus and cellular debris → plugging of small airways
5. Air trapping (collateral ventilation via pores of Kohn is absent at this age)
6. Hyperinflation → ventilation-perfusion mismatch → hypoxemia

Clinical Features

• Rhinorrhea, cough, low-grade fever
• Decreased feeding

• Tachypnea (respiratory rate >50/min in infants)
• Expiratory wheeze (diffuse, polyphonic)
• Subcostal/intercostal retractions
• Nasal flaring
• Hyperinflation of chest (barrel chest, increased AP diameter)
• Prolonged expiratory phase
• Crepitations (fine) on auscultation
• Fever (may be absent or low-grade)
• Feeding difficulties (tachypnea interferes with feeding)
• Apnea - especially in young infants (<2 months) and premature infants (may be only presenting sign)

Severity Assessment (Nelson's/AAP)

Investigations

• Primarily clinical diagnosis - investigations not routinely required
• Pulse oximetry - essential
• CXR: Hyperinflation, peribronchial thickening, patchy atelectasis (lower lobes); NOT diagnostic; not routinely indicated
• Nasopharyngeal aspirate/swab: RSV rapid antigen test or PCR (confirm diagnosis; useful for cohort isolation)
• ABG (only in severe disease)
• FBC not routinely needed

Treatment (AAP Clinical Practice Guideline 2014 - Nelson's aligned)

1. Oxygen therapy (most important intervention): Maintain SpO2 ≥90-92%
   • High-flow nasal cannula (HFNC) - increasingly used; reduces need for intubation
2. Hydration: IV fluids or nasogastric feeding if unable to feed orally
3. Nasal suction - bulb syringe or deep suction to clear secretions
4. Positioning: Upright (30-45°), head of bed elevated

• Bronchodilators (salbutamol/albuterol): A trial may be done; continue only if demonstrable clinical improvement
• Corticosteroids: NOT recommended (no benefit shown in multiple RCTs and meta-analyses)
• Antibiotics: NOT indicated (viral etiology); only for confirmed bacterial co-infection
• Ribavirin: Not routinely recommended
• Chest physiotherapy: Not recommended

• SpO2 <90% (or <92% in high-risk)
• Respiratory distress (RR >70/min, severe retractions)
• Apnea episodes
• Age <3 months
• Unable to feed (dehydration risk)
• Social circumstances

• Palivizumab (monthly IM injection during RSV season): Anti-RSV monoclonal antibody
  • Indications: Premature infants <29 weeks (1st RSV season); Chronic lung disease of prematurity; Hemodynamically significant congenital heart disease; Severe immunodeficiency
  • Reduces hospitalization by ~55%
• Nirsevimab (newer, single-dose long-acting monoclonal antibody): Now preferred in some guidelines for broader infant protection
• Hand hygiene, contact precautions, cohorting in hospital settings

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ACUTE BRONCHITIS

Definition

Etiology

• Viral (>90%): Influenza A/B, RSV, Rhinovirus, Parainfluenza, Adenovirus, hMPV
• Bacterial (uncommon as primary cause): Mycoplasma pneumoniae, Chlamydia pneumoniae, Bordetella pertussis

Clinical Features

• Dry cough progressing to productive cough
• Wheeze (in some)
• Low-grade fever
• Chest discomfort
• Normal lung exam (or mild wheeze/rhonchi)
• Duration: 1-3 weeks

Red Book 2021 (AAP/Nelson's): "Nonspecific cough illness/bronchitis in children does not warrant antimicrobial treatment. Prolonged cough may be caused by Bordetella pertussis, Mycoplasma pneumoniae, or Chlamydia pneumoniae - treat with appropriate antimicrobial when suspected/confirmed."

Treatment

• Supportive - hydration, rest, analgesics
• Antibiotics NOT indicated for routine acute bronchitis
• Consider macrolide (azithromycin) if pertussis or atypical organisms suspected (prolonged cough >2 weeks, paroxysms, post-tussive vomiting, whooping)
• Bronchodilators: If wheeze present

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CHAPTER 449: COMMUNITY-ACQUIRED PNEUMONIA

Definition

Etiology by Age Group (Nelson's)

Classification

• S. pneumoniae most common
• Sudden onset: High fever, rigors/chills, tachypnea, productive purulent cough
• Pleuritic chest pain (older children/adolescents)
• CXR: Lobar or segmental consolidation, air bronchogram
• WBC elevated with neutrophilia

• M. pneumoniae, C. pneumoniae
• Gradual onset over 3-5 days
• Low-grade fever, malaise, headache preceding respiratory symptoms
• Dry, non-productive cough; wheeze
• CXR: Bilateral diffuse interstitial or patchy infiltrates (worse than clinical examination suggests)
• WBC normal or mildly elevated
• "Walking pneumonia" - children ambulatory despite X-ray changes
• Extrapulmonary features of mycoplasma: Bullous myringitis (classic), hemolytic anemia (cold agglutinins), erythema multiforme, meningitis

• RSV, Parainfluenza, Influenza, Adenovirus, hMPV
• Common in <5 year olds
• Diffuse bilateral infiltrates, hyperinflation
• Adenovirus - can cause severe necrotizing pneumonia

• GBS (Group B Strep) - early onset (<3 days): Indistinguishable from sepsis
• Chlamydia trachomatis (afebrile pneumonia): 1-3 months; staccato cough; eosinophilia; positive maternal history

Clinical Features

• Cough, fever, tachypnea (most important signs)
• Chest pain, dyspnea
• Feeding difficulties (infants)
• Preceding URI (viral pneumonia)

• Tachypnea (most sensitive sign for pneumonia)

• Fever (>38.5°C)
• Decreased breath sounds / bronchial breathing (consolidation)
• Dullness to percussion
• Increased tactile fremitus
• Crepitations (fine/medium)
• Pleural rub (effusion)
• Accessory muscle use, grunting, nasal flaring, subcostal retractions (severe disease)

WHO Pneumonia Classification (Pediatric)

Investigations

• CXR (gold standard for confirmation)
• Pulse oximetry
• FBC: WBC elevation (bacterial); normal/low (viral/mycoplasma)
• CRP, Procalcitonin (elevated in bacterial; may guide antibiotic use)
• Blood culture: ~5-15% positive in CAP (higher yield in severe/hospitalized)
• Nasopharyngeal PCR multiplex (viral/atypical panel)
• Cold agglutinins: Positive (titer ≥1:64) in 50-75% of mycoplasma pneumonia
• Urine antigen: Pneumococcal (>14 yr), Legionella (all ages)
• Pleural fluid analysis (pH, LDH, protein, glucose, culture) if effusion present

Nelson's Severity Criteria for Hospitalization

• SpO2 <90%
• Respiratory distress (tachypnea, grunting, severe retractions)
• Altered mental status
• Age <3-6 months
• Unable to maintain oral hydration/feeding
• Failure of outpatient therapy (48 hours)
• Underlying conditions (immunodeficiency, sickle cell disease, CF)
• Complications: empyema, lung abscess, pneumatocele

• SpO2 <90% despite O2 therapy
• PICU-level respiratory support needed (CPAP, mechanical ventilation)

Treatment

• Ampicillin 150-200 mg/kg/day ÷ 6-hourly IV (S. pneumoniae usually susceptible)
• Add azithromycin if atypical pneumonia suspected (school-age)
• MRSA suspected (necrotizing, failed beta-lactam): Add vancomycin or clindamycin
• Cefotaxime/Ceftriaxone if ampicillin resistance suspected or partially immunized

• Ampicillin + Gentamicin (empiric) for early-onset
• Erythromycin/Azithromycin for Chlamydia trachomatis pneumonitis

• Bacterial CAP: 5 days (mild-moderate); 7-10 days (severe)
• Mycoplasma/Chlamydia: 5 days azithromycin or 7-14 days clarithromycin

• PCV13 (Pneumococcal conjugate vaccine): Scheduled immunization; reduces pneumococcal CAP by >50%
• Influenza vaccine: Annual; reduces influenza pneumonia
• Hib vaccine: Prevents H. influenzae CAP

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CHAPTER 261: TUBERCULOSIS (Mycobacterium tuberculosis)

Red Book 2021 / Nelson's 22nd Edition

Etiology

• Mycobacterium tuberculosis complex:
  • M. tuberculosis (most common globally)
  • M. bovis (from unpasteurized dairy; different epidemiology, natural pyrazinamide resistance)
  • M. africanum (West Africa)
  • Others (M. microti, M. canetti - rare)
• Acid-fast bacillus (AFB): Non-motile, aerobic, non-sporing, non-capsulated, weakly gram-positive

Transmission

• Airborne: respiratory droplets/droplet nuclei (1-5 μm) from infectious pulmonary/laryngeal TB
• Infectious period: Until 2 weeks after effective therapy
• Children with primary TB are rarely infectious (paucibacillary; cough less forceful)
• NOT transmitted by casual contact, sharing dishes, or urine/feces

Definitions (Red Book 2021 - Nelson's aligned)

Clinical Manifestations (Red Book 2021)

• Most infections in children are asymptomatic (LTBI)
• Symptoms appear 1 month to 2 years after infection
• Fever, weight loss/poor weight gain, cough, night sweats, chills
• Failure to thrive (infants)
• CXR findings: hilar/mediastinal lymphadenopathy (hallmark of primary childhood TB), atelectasis, segmental infiltrate, pleural effusion, miliary pattern
• Cavitation is uncommon in childhood TB (unlike adult reactivation)

• TB Meningitis: Most dangerous; common in children <5 yr; insidious onset; basilar meningitis; cranial nerve palsies; communicating hydrocephalus
• TB Lymphadenitis (Scrofula): Most common extrapulmonary form; cervical LN most often; firm, matted, non-tender → softens → collar-stud abscess
• TB Peritonitis: Ascites, abdominal pain
• TB Pericarditis: Fever, chest pain, pericardial effusion
• Skeletal TB (Pott's disease): Vertebral collapse; gibbus deformity; lower thoracic/upper lumbar
• Renal TB: Sterile pyuria (unusual in young children; adolescents)
• Congenital TB: Indistinguishable from neonatal sepsis; hepatosplenomegaly + bronchopneumonia

Diagnostic Tests

Tuberculin Skin Test (TST / Mantoux) - Red Book 2021

• Inject 5 TU PPD (0.1 mL) intradermally into volar forearm
• Read at 48-72 hours - measure transverse induration in mm

• False positive: BCG vaccination, NTM infection
• False negative: 10-40% of immunocompetent children with culture-confirmed TB may have negative TST initially; malnutrition, severe TB, viral infections (measles, varicella), young age

IGRA (Interferon-Gamma Release Assay)

• Measures ex vivo IFN-γ from T-lymphocytes stimulated with M. tuberculosis-specific antigens (ESAT-6, CFP-10)
• Not affected by BCG vaccination (more specific than TST)
• Preferred in: BCG-vaccinated children, children >5 years
• Less reliable in: Children <2 years (indeterminate results more common); severely immunocompromised
• Commercial tests: QuantiFERON-TB Gold Plus; T-SPOT.TB
• AAP (Nelson's): Either TST or IGRA acceptable; IGRA preferred in BCG-vaccinated; in children <2 yr, TST preferred or both tests

Bacteriological Confirmation

• Sputum/induced sputum AFB smear (ZN stain): 3 early morning samples
• Gastric aspirate (young children unable to expectorate): Most reliable bacteriological specimen in pediatric TB
• CBNAAT/GeneXpert MTB/RIF: Molecular; detects M. tuberculosis AND rifampicin resistance in 2 hours; preferred for pediatric diagnosis
• Culture: Gold standard; MGIT (liquid medium, 1-3 weeks) or LJ medium (6-8 weeks)
• CXR: Hilar lymphadenopathy, infiltrates, miliary pattern; HRCT if CXR inconclusive

Treatment of Tuberculosis (Red Book 2021 / Nelson's)

First-Line Drugs and Dosages (Pediatric)

Treatment Regimens

• 2HRZE / 4HR (2 months intensive: HRZE; 4 months continuation: HR) = 6 months total
• DOT (Directly Observed Therapy) strongly recommended

• 2HRZE(ethionamide or aminoglycoside) / 7-10HR = 9-12 months total
• Add dexamethasone (0.3-0.4 mg/kg/day, taper over 4-8 weeks) - reduces mortality/morbidity in TB meningitis
• Higher rifampicin dose: 20-30 mg/kg/day for CNS penetration

• Isoniazid 10 mg/kg/day x 9 months (9H) - preferred regimen in children
• Rifampicin 15 mg/kg/day x 4 months (4R) - alternative; better completion rates
• 3HP (once-weekly Isoniazid + Rifapentine x 12 weeks): Approved ≥2 years under direct observation

• At least 4-5 drugs to which organism is susceptible for 12-24 months from culture conversion
• Bedaquiline (FDA approved for adults; use in children ≥12 yr with MDR-TB per many experts)
• Consult expert for all MDR-TB cases

Prophylaxis / Chemoprophylaxis

• All children <5 yr exposed to active TB: Start isoniazid prophylaxis; test at 8-12 weeks
• HIV-infected children regardless of TST/IGRA: Isoniazid prophylaxis
• Pyridoxine (B6) supplementation: Co-administer with isoniazid in breastfed infants, malnourished children, adolescents

Prevention

• BCG vaccine: Live attenuated M. bovis; given at birth in endemic countries; 70-80% effective against TB meningitis and miliary TB; not routinely given in USA/UK
• Identify and treat LTBI contacts

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CHAPTER 453: ASTHMA (Reactive Airway Disease / Bronchial Asthma)

Definition (GINA 2024 / Nelson's)

• Airway inflammation (usually eosinophilic)
• Variable expiratory airflow limitation
• Respiratory symptoms (wheeze, dyspnea, chest tightness, cough) that vary over time and in intensity

Epidemiology

• Most common chronic respiratory disease of childhood
• Prevalence: ~9-10% in US children

• 50% develop symptoms before 5 years

• Leading cause of school absences and childhood hospitalization in the US
• Boys > Girls in childhood; Girls > Boys in adolescence

Etiology and Risk Factors

• IgE-mediated sensitization to common aeroallergens
• Family history of asthma or atopy (strongest risk factor)
• Atopic dermatitis ("eczema") in infancy - predicts asthma risk
• Food allergy (sensitization)

• Viral URTI - most common trigger in preschool children

• Indoor: Dust mites, cockroach allergen, pet dander, mold, tobacco smoke
• Outdoor: Pollen, air pollution (PM2.5, ozone)
• Tobacco smoke (prenatal and postnatal) - major independent risk factor

• Prematurity/low birth weight
• Obesity
• RSV/Rhinovirus bronchiolitis in infancy

Asthma Predictive Index (API) - Pediatric Risk Tool

• One major criterion: Parental asthma OR physician-diagnosed atopic dermatitis
• OR Two minor criteria: Wheezing apart from colds, peripheral blood eosinophilia ≥4%, evidence of allergic sensitization to foods

Pathophysiology

1. Allergen/trigger → IgE-mediated mast cell degranulation
2. Release: Histamine, LTC4/LTD4/LTE4 (cysteinyl leukotrienes), PGD2, tryptase
3. Bronchospasm, mucosal edema, mucus secretion

1. Eosinophil, T-lymphocyte, basophil recruitment
2. Cytokines: IL-4, IL-5, IL-13 (Th2-driven inflammation)
3. Prolonged bronchoconstriction and airway edema

• Smooth muscle hypertrophy and hyperplasia
• Sub-epithelial fibrosis (collagen deposition)
• Goblet cell metaplasia
• Mucosal gland hypertrophy
• Permanent reduction in lung function if uncontrolled

Clinical Features

• Wheeze (expiratory; diffuse)
• Dyspnea/breathlessness (episodic)
• Cough (dry, especially nocturnal and exercise-related; often only presenting symptom in cough-variant asthma)
• Chest tightness
• Symptoms worse at night (2-4 AM) and early morning
• Episodic, triggered nature

• Viral URTI (most common trigger in children <5 yr)
• Exercise ("exercise-induced bronchoconstriction")
• Cold air
• Allergen exposure
• Tobacco/wood smoke
• Strong odors, chemical fumes
• Emotional stress/crying
• GERD (can trigger)
• Aspirin/NSAIDs (aspirin-exacerbated respiratory disease - AERD; less common in children)

• Expiratory wheeze (polyphonic, diffuse)
• Prolonged expiratory phase
• Hyperinflated chest (chronic/severe)
• Accessory muscle use, intercostal retractions (acute)
• Pulsus paradoxus (>10-12 mmHg) in severe acute asthma
• Silent chest (no wheeze) in life-threatening asthma (no air movement)

Classification of Severity (NAEPP EPR-4 / Nelson's)

• Symptoms ≤2 days/week; night awakening ≤2x/month
• Normal FEV1/FVC between episodes; FEV1 ≥80% predicted
• SABA use ≤2 days/week

• Symptoms >2 days/week but not daily; nights >2x/month
• FEV1 ≥80%

• Daily symptoms; nights >1x/week
• FEV1 60-80%

• Continuous symptoms; frequent nights (7x/week)
• FEV1 <60%

Diagnosis

• Obstructive pattern: FEV1/FVC <0.8 (or <Lower Limit of Normal)
• Reversibility: ≥12% AND ≥200 mL improvement in FEV1 after bronchodilator
• Peak flow variability: Diurnal variation >20% over 2 weeks

• Bronchoprovocation testing (methacholine challenge) - if spirometry normal
• FeNO (Fractional exhaled Nitric Oxide): ≥25 ppb = eosinophilic airway inflammation; supports diagnosis
• Allergy testing: Skin prick test, specific serum IgE
• CXR: Hyperinflation, peribronchial thickening (may be normal between episodes)

• No reliable lung function tests
• Diagnosis based on symptom pattern + response to bronchodilators
• API used to predict persistent asthma

Management - Stepwise Approach (NAEPP / GINA 2024 / Nelson's)

• Allergen avoidance (dust mite covers, pet removal, cockroach control)
• Tobacco smoke avoidance (complete)
• Influenza vaccination annually
• Written Asthma Action Plan (AAP recommendation)
• Trigger identification and avoidance

• As-needed SABA (salbutamol/albuterol 90 mcg/puff, 2-4 puffs PRN)

• Low-dose Inhaled Corticosteroid (ICS) daily (e.g., budesonide, fluticasone, beclomethasone)
• Alternative: LTRA (Montelukast) - less effective than ICS

• Low-dose ICS + LABA (e.g., fluticasone/salmeterol)
• OR Medium-dose ICS alone
• Note: LABA monotherapy is NOT recommended in children (black box warning); always with ICS

• Medium-dose ICS + LABA

• High-dose ICS + LABA
• Add-on: LTRA, tiotropium
• Consider biologics: Omalizumab (anti-IgE; ≥6 yr with moderate-severe allergic asthma); Dupilumab (anti-IL-4Rα; ≥6 yr)

• High-dose ICS + LABA + oral corticosteroids (last resort; significant side effects)

Acute Exacerbation Management (Nelson's)

1. Supplemental oxygen (maintain SpO2 ≥95%)
2. Inhaled SABA: Salbutamol 2.5-5 mg (via nebulizer) or 4-8 puffs MDI + spacer every 20 minutes x 3, then hourly
3. Systemic corticosteroids:
   • Prednisolone/Prednisone: 1-2 mg/kg/day PO (max 40-60 mg) for 3-5 days
   • OR Dexamethasone 0.6 mg/kg IM/IV (max 16 mg) - 1-2 doses (equivalent efficacy, less side effects)
4. Ipratropium bromide (add-on in moderate-severe): 250-500 mcg nebulized Q20 min x 3 (reduces hospitalization)
5. Magnesium sulfate IV (25-75 mg/kg; max 2.5 g): For severe exacerbations not responding to initial therapy (bronchodilation + anti-inflammatory effect)
6. Heliox (70:30 helium:oxygen mixture): Reduces work of breathing; useful when not responding to standard therapy
7. IV Salbutamol: For severe/life-threatening; continuous infusion
8. Ketamine: Dissociative anesthetic with bronchodilator properties; for intubation
9. Non-invasive ventilation (CPAP/BiPAP): Before intubation
10. Mechanical ventilation: Last resort; permissive hypercapnia

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CHAPTER 422: RECURRENT ALLERGIC RESPIRATORY DISORDERS / LUNG PARENCHYMAL DISORDERS

The Atopic March (Nelson's)

• Sequential development of allergic conditions:
  • Atopic dermatitis (eczema) → infancy (0-2 yr)
  • IgE sensitization → food allergy
  • Allergic rhinitis → early childhood
  • Asthma → school age/adolescence
• Driven by Th2-dominant immune response + epithelial barrier dysfunction (filaggrin mutations)
• Co-morbid allergic rhinitis worsens asthma control (unified airway disease)

Allergic Rhinitis (Perennial/Seasonal)

• 10-30% of children; most common atopic condition
• Seasonal (SAR): Tree pollen (spring), grass (summer), ragweed (fall)
• Perennial (PAR): Dust mites, pet dander, mold, cockroaches (year-round)
• Symptoms: Sneezing paroxysms, watery rhinorrhea, nasal pruritus, nasal obstruction, itchy/watery eyes
• Treatment: INCS (most effective) → 2nd-generation antihistamines → LTRA → allergen immunotherapy for moderate-severe disease

Interstitial Lung Diseases (ILD) in Children (Children's Interstitial Lung Disease - chILD)

• Surfactant dysfunction disorders (SP-B, SP-C, ABCA3 mutations)
• Pulmonary interstitial glycogenosis
• Neuroendocrine cell hyperplasia of infancy (NEHI)
• Pulmonary alveolar proteinosis

• Hypersensitivity pneumonitis (organic dust exposure)
• Connective tissue disease-associated ILD (JIA, SLE)
• Sarcoidosis

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SUMMARY REFERENCE TABLE - Nelson's Chapter Guide

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PRANAVAHA SROTOVIKARA - CONTEMPORARY PEDIATRIC NOTES

M17 Units 2, 3 & 4 | Department of Kaumarabhritya

Sources cited throughout:

• [1] Tintinalli's Emergency Medicine: A Comprehensive Study, 9th ed. (McGraw-Hill)
• [2] Cummings Otolaryngology: Head and Neck Surgery, 7th ed. (Elsevier)
• [3] Scott-Brown's Otorhinolaryngology Head & Neck Surgery, Vol. 1 (CRC Press)
• [4] Red Book 2021: Report of the Committee on Infectious Diseases, 32nd ed. (AAP)
• [5] Murray & Nadel's Textbook of Respiratory Medicine, 7th ed. (Elsevier)
• [6] Fishman's Pulmonary Diseases and Disorders, 6th ed. (McGraw-Hill)
• [7] Harrison's Principles of Internal Medicine, 22nd ed. (McGraw-Hill)
• [8] Textbook of Family Medicine, 9th ed. (Elsevier)
• [9] Lippincott Illustrated Reviews: Pharmacology, 8th ed.
• [10] Rosen's Emergency Medicine, 10th ed. (Elsevier)
• [11] Harriet Lane Handbook, 23rd ed. (Johns Hopkins)
• [12] Goldman-Cecil Medicine, 27th ed. (Elsevier)

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UNIT 2: UPPER RESPIRATORY TRACT INFECTIONS

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1. RHINITIS / COMMON COLD

Definition

Etiology

• Rhinovirus - most common (15-20% of colds; 100+ serotypes); common cold [1]
• Coronavirus - >5%
• Adenovirus (types 3, 4, 7, 14, 21) - pharyngoconjunctival fever, acute respiratory disease [1]
• Parainfluenza virus - common cold, croup [1]
• Influenza virus, RSV, Enterovirus
• Allergic rhinitis (non-infectious): IgE-mediated; triggers include pollens (seasonal), dust mites, pet dander (perennial) [5]

Epidemiology

• Children average 6-8 colds per year; adults 2-4 per year [8]
• Peak: September to March (fall-winter)
• Transmission: Contact with secretions (hand-to-nose/eye contact > aerosol) [8]
• Allergic rhinitis affects 10-20% of the US/European population; estimated 18 million adults in the US affected [5]
• "The incidence of allergic rhinitis has been rising over the past 3 decades" - hygiene hypothesis proposed as explanation [5]

Pathophysiology

• Early phase (minutes): Allergen → IgE cross-linking on mast cells/basophils → degranulation → histamine, tryptase, leukotrienes → rhinorrhea, sneezing, nasal congestion within minutes
• Late phase (4-8 hours): Chemoattractants and adhesion molecules → infiltration of eosinophils, basophils, CD4+ lymphocytes → second wave of inflammatory mediators → persistent nasal congestion [5]

Clinical Features

• Nasal: Watery rhinorrhea (early) → thick mucopurulent (days 3-5; NOT a sign of bacterial infection [4])
• Nasal obstruction, sneezing paroxysms, post-nasal drip
• Systemic: Low-grade fever (especially in young children), sore throat, hoarseness, cough, malaise
• Duration: 7-10 days; cough may persist 2-3 weeks [8]
• Allergic rhinitis: Sneezing, watery rhinorrhea, nasal pruritus, itchy/watery eyes; associated with "allergic shiners" and "nasal crease"

Diagnosis

• Clinical; no routine investigations needed for viral rhinitis
• Allergic rhinitis: Skin prick testing or intradermal testing; specific IgE immunoassays (ImmunoCAP - similar sensitivity to skin testing) [5]
• "Both approaches carry a rare but important risk for anaphylaxis; testing centres must have personnel and equipment to deal with such emergencies" [5]

Complications

• Acute otitis media (most common in children <3 yr)
• Acute sinusitis
• Asthma exacerbation ("the early and late-phase reactions in AR mimic those of allergic asthma" [5])
• Adenoid hypertrophy with recurrent infections

Treatment

"Antimicrobial agents should not be given for the common cold. Mucopurulent rhinitis commonly accompanies the common cold and is not an indication for antimicrobial treatment." [4]

• Saline nasal drops/irrigation - effective and safe at all ages
• Analgesic/antipyretic: paracetamol or ibuprofen
• Humidification; adequate hydration
• OTC cough-cold preparations: NOT recommended in children <6 years (lack of efficacy, risk of harm - FDA warning) [8]

• Allergen avoidance - identify offending allergens; environmental control
• Saline irrigation - modest symptomatic benefit; reduces need for medications
• Intranasal corticosteroids (INCS) - most effective pharmacotherapy; first-line for moderate-persistent AR
• 2nd-generation antihistamines (cetirizine, loratadine)
• Leukotriene receptor antagonists (montelukast) - add-on therapy
• Immunotherapy (SCIT/SLIT): "Offers the only approach known to impact the natural history of the disease... results in suppression of allergen-specific IgE... treatment course 2-3 years" [5]
• FDA-approved SLIT agents: Grastek (timothy grass), Oralair (5 grasses), Odactra (dust mites), Ragwitek (ragweed) [5]

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2. PHARYNGITIS

Definition

Etiology

Red Book 2021 Key Statement [4]:

"Most cases of pharyngitis are viral in origin. Antimicrobial therapy should not be given to a child with pharyngitis in the absence of positive group A streptococcal testing... Group A streptococcal testing should only be performed in patients with signs and symptoms of pharyngitis without evidence of a viral upper respiratory infection."

Clinical Features

• Peak incidence: 5-15 years; uncommon <3 years
• Season: Late winter and early spring; incubation 2-5 days
• Sudden onset sore throat, high fever (38.5-40°C), painful swallowing
• Tonsillar exudate (cream/white), pharyngeal erythema
• Petechiae on soft palate
• Strawberry tongue
• Tender anterior cervical lymphadenopathy
• Absence of cough, rhinorrhea, hoarseness = suggest viral etiology, not GAS

• Fine, erythematous, sandpaper-like rash (blanches on pressure) starting on trunk → spreads to extremities
• Spares palms, soles, perioral area (circumoral pallor)
• Pastia's lines - accentuation in flexural creases (axilla, antecubital fossa)
• Strawberry tongue
• Desquamation after 3-4 days
• Result of erythrogenic toxin-producing strains of GAS

McIsaac/Centor Criteria (predicting GAS) [8]:

Diagnostic Tests [8]:

• Throat culture (gold standard): 5% sheep blood agar; sensitivity 96%; 24-48 hours
• RADT (Rapid Antigen Detection Test): Sensitivity 60-80%, specificity 90-95%; positive RADT in children → treat; negative RADT in children → confirm with culture (children at higher ARF risk); negative RADT in adults does not require backup culture

Complications of Untreated GAS [8]:

• Peritonsillar abscess (most common), retropharyngeal abscess
• Otitis media, sinusitis, mastoiditis

• Acute Rheumatic Fever (ARF) - prevented by adequate antibiotic therapy within 9 days
• Post-streptococcal Glomerulonephritis (PSGN) - antibiotics do NOT prevent PSGN

Treatment - Antibiotic Therapy [4]:

Red Book 2021 [4]: "Penicillin V is the drug of choice for GAS pharyngitis. Prompt administration shortens the clinical course, decreases risk of transmission, suppurative sequelae, and prevents ARF even when administered up to 9 days after illness onset."

Short-course treatment (<10 days) for GAS pharyngitis, particularly with penicillin V, "is associated with inferior bacteriologic eradication rates." [4]

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3. ADENOID HYPERTROPHY

Definition and Anatomy

Epidemiology

• Common in children aged 3-10 years
• Adult adenoid hypertrophy: "could indicate a lymphoproliferative disorder or HIV infection" [8]

Clinical Features [8]:

• Nasal obstruction (chronic, bilateral)
• Rhinorrhea, snoring, mouth breathing
• Hyponasal speech (adenoid voice)
• Obstructive sleep-disordered breathing / OSA
• Recurrent otitis media with effusion (OME/glue ear) - Eustachian tube dysfunction → conductive hearing loss
• Adenoid facies: "Children with long-standing nasal obstruction tend to have elongated, narrow faces with open-mouth breathing" [8]
• Chronic sinusitis: "Adenoid hypertrophy can cause sinusitis secondary to nasal obstruction, mucus stasis, and subsequent infection" [8]
• "Chronic adenoiditis can mimic sinusitis in children... symptoms may be identical, and the disorders often coexist" [8]

Diagnosis

• Clinical
• Lateral neck X-ray - confirms adenoid size relative to nasopharyngeal airway
• Flexible nasopharyngoscopy (gold standard for visualization)
• Audiometry/tympanometry for OME assessment

Treatment [8]:

• "Limited evidence suggests that intranasal corticosteroids may significantly improve nasal obstruction symptoms in children with moderate to severe adenoidal hypertrophy. This improvement may be associated with a reduction of adenoid size." (Cochrane Collaboration) [8]
• Antibiotics for acute superinfection

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4. TONSILLITIS

Etiology

Classification

1. Acute tonsillitis - single episode; viral or bacterial
2. Recurrent tonsillitis - multiple discrete acute episodes
3. Chronic tonsillitis - persistent infection >3 months
4. Tonsillar hypertrophy - enlargement with/without infection

Peritonsillar Abscess (Quinsy)

• Suppurative complication: pus between tonsil and superior pharyngeal constrictor
• Features: Unilateral tonsillar swelling, uvular deviation to opposite side, trismus (lockjaw), "hot-potato" muffled voice, drooling, fever [10]
• Treatment: Needle aspiration or I&D + antibiotics; tonsillectomy considered

Tonsillectomy - Paradise Criteria [2]:

Treatment

• Viral tonsillitis: Symptomatic - analgesics, fluids, throat lozenges; no antibiotics [4]
• GAS bacterial tonsillitis: Same as GAS pharyngitis - Penicillin V/Amoxicillin x 10 days [4]
• Peritonsillar abscess: I&D or needle aspiration + amoxicillin-clavulanate or clindamycin IV

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5. CROUP (Viral Laryngotracheobronchitis)

Definition

Etiology

• Parainfluenza virus type 1 - "most commonly identified in cases of croup" [3]; also types 2 and 3
• Rhinovirus, Influenza A and B, RSV, Human Metapneumovirus, Adenovirus, Coronavirus [1]
• Measles (in endemic areas)

Epidemiology

• Age: 6 months to 6 years (peak 1-2 years) [1]
• Season: Late fall and early winter (biennial peaks - odd years for parainfluenza type 1)
• Accounts for ~15% of respiratory tract disease in pediatric outpatients

Pathophysiology

• Subglottis = narrowest part of pediatric airway → small diameter reduction → marked resistance increase (∝ 1/r⁴)
• Inspiratory stridor = turbulent airflow through narrowed subglottic airway

Clinical Features [1]:

• Prodrome (1-3 days): Rhinorrhea, coryza, cough, low-grade fever
• Classic triad:
  1. Harsh, barking/seal-like cough
  2. Hoarse voice/dysphonia
  3. Inspiratory stridor
• Worse at night (characteristic nocturnal exacerbation)
• Most children not toxic-appearing (contrast with epiglottitis)
• Most self-limited: resolves in 3-7 days

Westley Croup Score [1]:

Differential Diagnosis - Croup vs Epiglottitis [3]:

Radiology

• AP neck X-ray: "Steeple sign" - subglottic pencil-like narrowing (viral croup)
• Lateral neck X-ray: "Thumbprint sign" - swollen epiglottis (epiglottitis)

Treatment [3] [10]:

"A recent Cochrane review found when corticosteroids were compared to placebo in treatment for croup, dexamethasone and budesonide were effective in relieving symptoms as early as 6 hours after treatment, resulting in reduced hospital stay and fewer hospital re-admissions. Some clinical improvement can occur within 30 minutes of glucocorticoid dose." [3]

• Dexamethasone 0.6 mg/kg PO/IM/IV (single dose; max 10 mg) - first-line; standard of care [10]
• "Glucocorticoids (usually given as a single oral dose of dexamethasone) reduce symptoms, hospitalizations, and length of stay in the emergency department." [10]

• "If airway obstruction is severe, short-term relief can be achieved by nebulizing adrenaline (1 ml/kg of 1:1000 up to maximum 5 ml) with oxygen" [3]
• Racemic epinephrine 0.5 mL of 2.25% solution in 3 mL NS (nebulized)
• "Treatment of moderate to severe croup includes vaporized epinephrine in addition to glucocorticoids. Patients can be discharged from the ED after a post-treatment observation period." [10]
• Both dexamethasone and nebulized adrenaline "have both been shown to reduce length of hospital stay in management of croup" [3]

• "A small number of children with croup (<5%) will require intubation" [3]
• Use smaller ETT than calculated for age (subglottic edema)
• Heliox in refractory cases

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6. LARYNGITIS

Definition

Etiology [8]:

• Viral infections: most common cause ("often associated with other upper respiratory tract symptoms")
• Voice overuse
• Gastroesophageal reflux disease (GERD)
• Fungal (Candida): "found in immunocompromised patients; patients using inhaled steroids; and those using long-term, broad-spectrum antibiotics"
• Rare: Tuberculosis, syphilis [8]

Clinical Features [7] (Harrison's 22e):

• Hoarseness - cardinal symptom; may progress to aphonia
• Dry or productive cough
• Throat pain, tickling, globus sensation
• Usually self-limited (viral): resolves in 7-10 days
• Stridor may accompany in children with small airways

Treatment [8]:

• "Treatment is conservative, and recommendations include relative voice rest and avoidance of inhalational substances such as cigarette smoke or other irritating substances. Humidification may be helpful."
• "Symptoms from viral laryngitis usually improve within days."
• "A Cochrane review concluded that the risks of antibiotics outweigh the benefits in treatment." [8]
• Fungal laryngitis: "Topical treatment includes nystatin, miconazole, or clotrimazole; systemic therapy includes fluconazole or ketoconazole." [8]
• "Consider other causes if symptoms persist" → ENT referral if hoarseness >3 weeks (rule out papillomatosis, malignancy)

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7. EPIGLOTTITIS (Supraglottitis)

Definition

Etiology [8]:

• Pre-Hib vaccine era: H. influenzae type b (Hib) - predominant cause in children
• Post-Hib vaccine era (current): "Epiglottitis is much less common in the pediatric population with routine Haemophilus influenzae type b (Hib) vaccination and is now more often seen in adults." [8]
• Current organisms: S. pneumoniae, S. aureus, MRSA, non-typeable H. influenzae, GAS
• "It is often more insidious in adults but can still progress to airway obstruction." [8]

Clinical Features - The 4 Ds [8]:

"Signs and symptoms of epiglottitis include a rapidly developing sore throat, high fever, restlessness, and lethargy. A 'supraglottic,' muffled voice is common. Many patients have difficulty with their saliva and drool. Classically, these patients are in a sitting position leaning forward because this position tends to alleviate obstructive symptoms from the supraglottic swelling. They may show signs of 'air hunger' or may have stridor."

• High fever (39-40°C), sudden onset
• Tripod/sniffing position: Sits upright, leans forward, neck extended
• "Drooling, posturing, and air hunger are classic signs of epiglottitis." [8]
• Mortality: "6% to 7% have been reported in adults" [8]

Critical warning [8]: "Croup, tonsillitis, peritonsillar abscess, and other neck infection may be incorrectly diagnosed in these patients." "Epiglottitis occurs mainly in children age 2 to 7 years, although infants, older children, and adults can be affected."

Radiology [8]:

• "A lateral neck radiograph showing a thumbprint sign can be diagnostic of epiglottitis, but visualization of the larynx is paramount." [8]
• Vallecula sign absent

Management - EMERGENCY [8] [10]:

1. DO NOT examine pharynx with tongue depressor or agitate child - risk of complete airway obstruction
2. Allow child to remain in preferred position; parent at bedside
3. Assemble team (anesthesia, ENT, ICU) immediately
4. Controlled intubation in OR/ICU - nasotracheal or RSI; ETT 0.5-1 size smaller than calculated
5. IV Ceftriaxone 50 mg/kg Q24h (covers H. influenzae, S. pneumoniae)
6. IV Dexamethasone to reduce edema
7. Extubate when direct laryngoscopy shows resolution (24-48 hours)
8. Complete 7-10 day antibiotic course orally
9. Prevention: Hib vaccine - "dramatically reduced pediatric Hib epiglottitis" [8]

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UNIT 3: LOWER RESPIRATORY TRACT INFECTIONS

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8. ACUTE BRONCHITIS

Definition

Etiology [6]:

"Respiratory viruses, including rhinovirus, coronavirus, parainfluenza virus, respiratory syncytial virus, human metapneumovirus, and influenza virus, are responsible for up to 90% of cases."

• Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae: "most frequently identified bacteria in immunocompetent adults with acute uncomplicated bronchitis" [6]

Clinical Features [6]:

• "Cough, with or without sputum production, is the hallmark of acute bronchitis."
• "Although patients with purulent sputum are more frequently prescribed antibiotic therapy, sputum appearance is an unreliable surrogate for bacterial infection." [6]
• "On average, cough lasts for 10 to 20 days but can persist for more than a month." [6]
• Headaches, rhinorrhea, mild constitutional symptoms

Management [6]:

"Given the self-limited nature of acute bronchitis, the goal of clinical evaluation is to exclude potentially life-threatening diagnoses whose symptoms may overlap with acute bronchitis, including pneumonia and exacerbations of asthma, COPD, and congestive heart failure." [6]

• "Guidelines do not recommend the routine prescription of antitussives, inhaled bronchodilators, oral corticosteroids, or other oral anti-inflammatory medications." Management is therefore supportive. [6]
• Antibiotics NOT recommended:

  "Guidelines from professional societies and the CDC uniformly recommend avoiding antibiotics for acute uncomplicated bronchitis. Indeed, the IDSA includes a recommendation to avoid antibiotics for acute bronchitis as one of their five statements for the Choosing Wisely campaign." [6] "Despite these recommendations, in an analysis of ambulatory care prescription practices in the US from 1996 to 2010, the overall antibiotic prescription rate for acute bronchitis was 71%, a rate that actually rose during the study period." [6]

• Red Book 2021 [4]: "Nonspecific cough illness/bronchitis in children does not warrant antimicrobial treatment. Prolonged cough may be caused by Bordetella pertussis, Mycoplasma pneumoniae... when suspected clinically or confirmed, appropriate antimicrobial therapy is indicated."

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9. BRONCHIOLITIS

Definition

Epidemiology [2]:

• "Between 2% and 3% of children younger than 12 months in the United States are hospitalized with a diagnosis of bronchiolitis." [2]
• Peak age: 2-6 months; virtually all children infected with RSV by age 2 years
• Season: November-April (RSV season in Northern Hemisphere)
• Risk factors for severe disease: prematurity, chronic lung disease of prematurity (BPD), hemodynamically significant congenital heart disease, immunodeficiency, age <12 weeks

Etiology [2] [1]:

• RSV - most common; majority of cases; types A and B
• Human Metapneumovirus (hMPV) - second most common; clinically similar to RSV
• Rhinovirus (associated with increased risk of subsequent asthma/recurrent wheeze)
• Parainfluenza type 3, Adenovirus, Influenza, Bocavirus

Pathophysiology [2]:

Clinical Features [2]:

• Tachypnea (RR >50/min in infants)
• Expiratory wheeze (diffuse)
• Subcostal/intercostal retractions, nasal flaring
• Hyperinflation of chest (barrel chest)
• Prolonged expiratory phase
• Fine crepitations on auscultation
• Apnea - particularly in young infants and premature infants (may be the only presenting sign)
• Feeding difficulties (tachypnea interrupts feeding)

Investigations [2]:

• "Radiologic findings may include air trapping, hyperinflation, centrilobar thickening, and bronchiolar dilation; foreign body should be in the differential diagnosis." [2]
• CXR not routinely required (self-limited viral illness)
• Pulse oximetry - essential
• Nasopharyngeal RSV rapid antigen test / PCR (for cohort isolation in hospital)

Treatment - Supportive Care Mainstay [2]:

"Symptoms are usually self-limited, and although inhaled bronchodilators may improve symptoms, use of antibiotics, steroids, and oral bronchodilators is not well supported by research." [2]

1. Oxygen therapy (most important): Maintain SpO2 ≥90-92%; High-flow nasal cannula (HFNC) increasingly used
2. Hydration: IV fluids or nasogastric feeding if unable to feed orally
3. Nasal suction: Bulb syringe or deep suction
4. Positioning: upright (30-45°), head elevated

• Bronchodilators (salbutamol): trial acceptable; continue only if demonstrable improvement
• Corticosteroids: NOT recommended (no benefit in multiple RCTs)
• Antibiotics: NOT indicated (viral; only for proven bacterial co-infection)
• Chest physiotherapy: not recommended

• Palivizumab (monthly IM injection, RSV season): Anti-RSV monoclonal antibody. "Should not be used broadly for RSV prophylaxis; however, its use in very specific subpopulations of infants or toddlers may be beneficial." [2]
  • Indications: Premature infants <29 weeks (1st RSV season); BPD; hemodynamically significant CHD; severe immunodeficiency
  • Reduces RSV hospitalization by ~55%
• "Vigilant measures to prevent nosocomial spread to other hospitalized patients is important." [2]
• Nirsevimab (newer single-dose long-acting monoclonal antibody) - broader protection

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10. COMMUNITY-ACQUIRED PNEUMONIA

Definition

Etiology by Age Group [1]:

Symptoms and Physical Signs [1]:

"Rapid respiratory rate is a simple screening tool for pneumonia." [1]

"The combination of fever plus either tachypnea, decreased breath sounds, or fine crackles predicts radiographic pneumonia with a sensitivity of 93% to 96%." [1]

• Lower chest indrawing/subcostal retractions = more severe pneumonia
• Grunting, nasal flaring, accessory muscle use
• Cough (less common in neonates/very young; productive cough rarely seen before late childhood)
• "In infants, intermittent apnea, grunting, and an inability to feed are surrogate markers of dyspnea." [1]

WHO Classification (Pediatric) [1]:

Chest X-Ray [1]:

"The chest radiograph is not the gold standard of diagnosis, because it is neither 100% sensitive nor 100% specific and may be falsely negative (e.g., when clinical disease precedes radiographic changes) or falsely positive." [1]

"Chest radiographs do not reliably distinguish between bacterial and viral causes." [1]

"Several studies and major guidelines state that imaging should not be performed routinely in children with mild, uncomplicated acute lower respiratory tract infections." [1]

1. Toxic-appearing child with respiratory findings
2. Age 0-3 months with fever + respiratory symptoms (full sepsis evaluation)
3. Child <5 yr with temperature >39°C lasting ≥5 days + WBC ≥20,000/mm³ with no clear source
4. Suspicion of complication: pleural effusion, pneumothorax, empyema
5. Failure to improve with appropriate antibiotic therapy

Treatment - Empiric Antibiotics [1]:

• 3 months - 5 years: High-dose amoxicillin (80-100 mg/kg/day) ÷ TID PO - "remains the initial drug of choice in suspected bacterial pneumonia... all presume the most frequent cause to be S. pneumoniae" [1]
• 5-18 years: Amoxicillin ± azithromycin (for atypical coverage); "macrolide monotherapy is a reasonable initial choice" if atypical strongly suspected; growing concern for high pneumococcal macrolide resistance [1]

• "In hospitalized children in whom the etiology of pneumonia is unclear, β-lactams plus macrolides should be used as first-line therapy for children 5 years and older." [1]
• MRSA suspected: add Vancomycin or Clindamycin
• Third-generation cephalosporin (ceftriaxone/cefotaxime): if penicillin resistance high, incompletely immunized, or life-threatening infection

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11. TUBERCULOSIS

Etiology [4]:

• M. tuberculosis complex: M. tuberculosis, M. bovis, M. africanum
• "Acid-fast bacillus"; airborne transmission via respiratory droplet nuclei (1-5 μm)
• "Children with primary TB are rarely infectious" (paucibacillary; less forceful cough)

Clinical Manifestations - Pulmonary TB [4]:

"Most infections caused by M tuberculosis complex in children and adolescents are asymptomatic. When pulmonary TB occurs, clinical manifestations most often appear 1 month to 2 years after infection and include fever, weight loss or poor weight gain, cough, night sweats, and chills."

"Although cavitation is a typical presentation of reactivated TB in adults, cavitation is uncommon in childhood TB." [4]

Extrapulmonary TB [4]:

• TB Meningitis (most dangerous; common in children <5 yr): basilar meningitis, CN palsies, communicating hydrocephalus
• TB Lymphadenitis (Scrofula): cervical LN, matted, non-tender; collar-stud abscess
• TB Peritonitis, TB Pericarditis
• Skeletal TB (Pott's disease): vertebral collapse, gibbus deformity
• "Gastrointestinal tract TB can mimic inflammatory bowel disease." [4]
• "Renal TB is unusual in younger children but can occur in adolescents." [4]
• "Congenital TB can mimic neonatal sepsis, or the infant may come to medical attention in the first 90 days of life with bronchopneumonia and hepatosplenomegaly." [4]

Diagnostic Tests

TST (Mantoux) - Red Book 2021 [4]:

• Inject 5 TU PPD (0.1 mL) intradermally into volar forearm; read at 48-72 hours
• "The standardized time for assessing the TST result is 48 to 72 hours after administration. The diameter of induration is measured transversely to the long axis of the forearm." [4]

• "Approximately 10% to 40% of immunocompetent children with culture-documented TB disease do not react initially to a TST." [4]
• False positives: BCG vaccination, NTM infection

IGRA (Interferon-Gamma Release Assay) [4]:

"IGRAs measure ex vivo interferon-gamma production from T lymphocytes in response to stimulation with antigens specific to M tuberculosis complex... The IGRA antigens used are not found in BCG or most pathogenic nontuberculous mycobacteria."

• Preferred in BCG-vaccinated children (avoids false-positive TST)
• TST preferred in children <2 years (more indeterminate IGRA results)
• "In people previously vaccinated with BCG, IGRA is preferred to avoid a false-positive TST result." [4]

Bacteriological Confirmation [4]:

• Gastric aspirate (best specimen in young children): "Early-morning gastric aspirate, obtained with a nasogastric tube on awakening before ambulation or feeding. Aspirates collected on 3 separate mornings should be submitted for AFB staining and culture." [4]
• GeneXpert MTB/RIF (CBNAAT/NAAT): Molecular; detects M. tb + rifampicin resistance in 2 hours; "Positive results from a rapid molecular method increasingly are also considered confirmatory" [4]
• Culture: Gold standard; MGIT (liquid - 1-3 weeks) or LJ medium (6-8 weeks)
• "Fluorescent staining methods for specimen smears are more sensitive than traditional Kinyoun acid-fast smears." [4]

Treatment Regimens (Red Book 2021 / AAP) [4]:

First-Line Drug Dosages (Pediatric):

"Many experts recommend using a daily rifampin dose of 20-30 mg/kg/day for infants and toddlers and for serious forms of tuberculosis, such as meningitis and disseminated disease." [4]

Standard Regimens:

• Pulmonary TB (new case, drug-susceptible): 2HRZE / 4HR (6 months total)
• Extrapulmonary TB (except meningitis): Same 6-month regimen
• TB Meningitis + Miliary TB: 2HRZE(ethionamide or aminoglycoside) / 7-10HR (9-12 months total); add dexamethasone

TBI (Latent TB) Treatment [4]:

"Pyridoxine supplementation: Exclusively breastfed infants and children on meat-and-milk-deficient diets; symptomatic children with HIV." [4]

MDR-TB [4]:

"For cases of MDR TB disease, the treatment regimen needed for cure should include at least 4 or 5 antituberculosis drugs to which the organism is susceptible... Therapy for MDR TB is administered for 12 to 24 months from the time of culture conversion to negativity." [4]

• Bedaquiline: FDA approved for adults; "many experts recommend its use in children 12 years and older" [4]
• "An expert in DR TB should be consulted for all drug-resistant cases." [4]

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UNIT 4: RECURRENT ALLERGIC RESPIRATORY DISORDERS

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12. ASTHMA (Reactive Airway Disease)

Definition

Epidemiology

• Most common chronic respiratory disease of childhood; ~9-10% prevalence in US children

• 50% develop symptoms before 5 years of age [8]

• Atopic march: Atopic dermatitis → food sensitization → Allergic rhinitis → Asthma

Pathophysiology [9]:

• Allergen/trigger → IgE-mediated mast cell degranulation → histamine, LTC4/LTD4/LTE4, PGD2 → bronchospasm, edema, mucus secretion

• Eosinophil/T-lymphocyte recruitment; IL-4, IL-5, IL-13 (Th2) cytokines → prolonged bronchoconstriction

• Smooth muscle hypertrophy, sub-epithelial fibrosis (collagen deposition), goblet cell metaplasia, gland hypertrophy

Goals of Therapy [9]:

"Drug therapy for long-term control of asthma is designed to reverse and prevent airway inflammation. The goals are to decrease the intensity and frequency of asthma symptoms, prevent future exacerbations, minimize limitations in activity, and minimize adverse effects. The GINA guidelines recommend that all patients with asthma should receive treatment with a long-term controller medication and a reliever medication." [9]

Pharmacological Treatment - GINA 2024 / NAEPP Step Approach [9]:

"ICSs are the foundation of therapy for controller medications in patients with asthma. Corticosteroids inhibit the release of arachidonic acid through inhibition of phospholipase A2, thereby producing direct anti-inflammatory properties in the airways. To be most effective in controlling inflammation, these agents must be used regularly." [9]

• Decreases inflammatory cascade (eosinophils, macrophages, T lymphocytes)
• Reverses mucosal edema
• Decreases capillary permeability
• Inhibits leukotriene release
• "After several months of regular use, ICSs reduce the hyperresponsiveness of airway smooth muscle to a variety of bronchoconstrictor stimuli." [9]

• Local: Hoarseness, oropharyngeal candidiasis (due to local immune suppression)
• Prevention: "Patients should be instructed to rinse the mouth in a 'swish-and-spit' method with water following use of the inhaler." [9]
• Use of large-volume spacer "can limit the amount of drug deposited in the mouth, thus reducing the chances of oropharyngeal candidiasis" [9]

• "Patients with a severe exacerbation of asthma may require IV methylprednisolone or oral prednisone to reduce airway inflammation."
• "In most cases, suppression of the hypothalamic-pituitary-adrenal axis does not occur during the oral prednisone burst... thus, a dose taper is unnecessary prior to discontinuation." [9]

Acute Exacerbation Management [10]:

1. Supplemental oxygen (SpO2 ≥95%)
2. Inhaled SABA (salbutamol 2.5-5 mg nebulized or 4-8 puffs MDI + spacer Q20 min x 3)
3. Systemic corticosteroids: Prednisolone 1-2 mg/kg/day PO (max 40-60 mg) x 3-5 days; OR Dexamethasone 0.6 mg/kg IM/IV x 1-2 doses
4. Ipratropium bromide (add-on in moderate-severe): reduces hospitalization rate
5. IV Magnesium sulphate (25-75 mg/kg; max 2.5 g): for severe exacerbations not responding to initial therapy
6. Heliox (70:30 He:O2): reduces work of breathing in severe upper airway obstruction
7. NIV (CPAP/BiPAP) before intubation
8. Mechanical ventilation (last resort - status asthmaticus): permissive hypercapnia

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13. RECURRENT ALLERGIC RESPIRATORY DISORDERS

Unified Airway Disease Concept

"Immunotherapy... may also diminish the onset of additional atopic disorders, such as asthma in patients with AR." [5]

Management of Allergic Rhinitis (AR) - Murray & Nadel [5]:

• "The vast majority of patients are effectively treated with pharmacotherapy and allergen avoidance."
• "Saline irrigation results in modest symptomatic improvement and may reduce the need for medications with more significant side-effect profiles." [5]
• Allergen identification: Skin prick testing; ImmunoCAP specific IgE assay; knowledge of local flora essential [5]

"Although pharmacologic treatment of AR may be quite effective in managing symptoms, immunotherapy offers the only approach known to impact the natural history of the disease." [5]

• SCIT (subcutaneous): once/twice-weekly escalating injections; most studied; 2-3 year course
• SLIT (sublingual): avoids injection; may be administered at home
• FDA-approved SLIT (US): Grastek, Oralair, Odactra, Ragwitek [5]
• Mechanism: "shift in allergen-specific T cells to a regulatory phenotype results in suppression of type 2 T-helper inflammatory cytokines and enhanced production of IL-10 and antigen-specific IgG4" [5]

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14. LUNG PARENCHYMAL DISORDERS

Interstitial Lung Disease (ILD) - Overview

• "ABPA develops in genetically susceptible patients with asthma or CF because of increased activity of A. fumigatus-specific Th2 CD4+ cells." [6]
• IgE molecules on mast cells recognize Aspergillus antigens → mast cell degranulation → vasodilatation, vascular leakage → anti-Aspergillus IgG enters bronchi → IgG-Aspergillus immune complexes → complement activation → pulmonary damage [6]
• "Some 7% to 14% of patients with poorly controlled asthma and 7-9% with CF have ABPA" [6]
• Features: recurrent bronchospasm, brown mucus plugs, fleeting pulmonary infiltrates, peripheral eosinophilia, elevated serum IgE, positive immediate skin test to Aspergillus

• Definition: "Productive cough for at least 3 months in at least 2 consecutive years"
• Pathology: Hypertrophy of mucous glands in bronchi (Reid index - ratio of gland-to-wall thickness >0.4); goblet cell metaplasia in smaller bronchi/bronchioles
• Etiology: Smoking (primary), air pollution, recurrent infections
• Complications: COPD, cor pulmonale, respiratory failure

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QUICK REFERENCE - KEY EVIDENCE STATEMENTS

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