Suspecting Pneumonia in Paediatrics: History & Examination

History (Key Questions to Ask)

• Cough - duration and character
• Difficulty breathing / fast breathing - main symptom to pursue
• Inability to feed (infants <2 months: stopped feeding well; older children: unable to drink/eat)
• Fever - how long, how high
• Altered sensorium - excessive drowsiness, difficult to wake, convulsions
• Turning blue (cyanosis episodes) or irregular breathing / apnoeic spells
• Antecedent illness - recent measles increases pneumonia risk significantly
• Risk factors - malnutrition, prematurity, crowding, passive smoke exposure, day-care attendance

Physical Examination (What to Look For)

1. Fast Breathing (Tachypnoea) - Most Important Sign

• Count for a full minute with the child calm; chest/abdomen exposed.
• Repeat in infants <2 months if borderline (their rate is often erratic).

2. Chest Indrawing (Lower Chest Wall Retractions)

• Lower chest wall draws in on inspiration - indicates increased work of breathing.
• Present alone = severe pneumonia; more ominous than fast breathing alone.

3. Danger Signs (suggest Very Severe Disease)

• Unable to drink or breastfeed
• Vomits everything
• Convulsions
• Abnormally sleepy / unconscious / difficult to wake
• Stridor at rest

4. Other Examination Findings

• Nasal flaring
• Grunting (especially in neonates)
• Cyanosis - check in good light; sign of hypoxia
• Auscultation: reduced air entry, bronchial breathing, crackles (crepitations)
• Fever or hypothermia (hypothermia is a warning sign in neonates)
• Pulse oximetry: SpO2 <94% supports diagnosis and indicates severity

IMCI Classification Summary

Note: In severely malnourished children, fast breathing and chest indrawing may be absent or blunted despite significant pneumonia - these children need extra careful evaluation.

10 Main Risk Factors for Asthma

1. Atopy (Most Important)

2. Genetic Predisposition

3. Allergen Exposure

• Indoor: house dust mite, cockroach, animal dander, indoor fungi
• Outdoor: pollens, outdoor fungi Chronic allergen exposure leads to sensitization, persistent airway inflammation, and remodelling.

4. Tobacco Smoke (Active & Passive)

5. Respiratory Infections in Early Life

6. Obesity

7. Occupational Sensitizers

8. Gender & Hormonal Factors

• In childhood: asthma is more common in boys
• After puberty: prevalence shifts - women are more affected
• Hormonal fluctuations (menstrual cycle, pregnancy, menopause) can influence asthma severity

9. Socioeconomic Status & Environment

10. Drugs

• Beta-blockers (including eye drops)
• Aspirin / NSAIDs (aspirin-exacerbated respiratory disease - AERD)
• ACE inhibitors (cause cough, can trigger bronchospasm)

Endogenous factors: atopy, airway hyperresponsiveness, genetics, gender, ethnicity Environmental factors: allergens, tobacco, infections, obesity, occupational exposure, socioeconomic status

10 Risk Factors for Asthma in Paediatrics

1. Atopy / Personal or Family History of Allergic Disease

2. Family History of Asthma

3. Maternal Smoking & In Utero Smoke Exposure

4. Early-Life Viral Respiratory Infections

5. Abnormal Lung Function at Birth / Prematurity

6. Male Sex

7. Indoor Allergen Exposure

8. Caesarean Section Delivery

9. Obesity / Rapid Early Weight Gain

10. Prenatal & Perinatal Nutritional Factors

• Vitamin D deficiency in the mother increases asthma risk in the child
• High maternal sugar intake is associated with increased childhood asthma
• Maternal supplementation with vitamins C & E, zinc, and omega-3 fatty acids may be protective
• Breastfeeding reduces early wheezing, though its effect on long-term asthma is less clear

Key paediatric concept: The Tucson Children's Respiratory Study identified 4 wheeze phenotypes in children. "Persistent wheezers" (the true future asthmatics) were predicted by: young maternal age, elevated IgE at 9 months, parental asthma, in-utero smoke exposure, reduced lung function at birth, and male sex.

Risk Factors for Pneumonia in Paediatrics

HOST FACTORS

• HIV infection - Pneumocystis jirovecii pneumonia accounts for at least 25% of all pneumonia deaths in HIV-infected infants
• Immunoglobulin deficiency (primary or secondary)
• Chemotherapy / stem cell transplant
• Chronic underlying diseases (congenital heart disease, cystic fibrosis, sickle cell disease)

ENVIRONMENTAL FACTORS

Quick Summary Table

Note: In severely malnourished children, classical signs of pneumonia (fast breathing, chest indrawing) may be absent or blunted, making clinical assessment particularly challenging.

2 Categories of TB Treatment (WHO / RNTCP Framework)

CATEGORY I - New Cases

• New sputum smear-positive pulmonary TB
• New sputum smear-negative pulmonary TB (with X-ray evidence)
• New cases of severe extrapulmonary TB (e.g., TB meningitis, TB spine, miliary TB, pericardial TB, abdominal TB)
• New severe concomitant HIV disease

CATEGORY II - Retreatment Cases

• Relapse - previously treated, declared cured/treatment completed, now sputum positive again
• Treatment failure - sputum smear still positive at 5 months or beyond
• Treatment after default (TAD) - interrupted treatment for ≥2 months, returned with sputum positive
• Others - previously treated cases, smear-positive (unknown or unclassified outcome)

Key Differences at a Glance

Important note (Modern update): WHO's 2022 guidelines and India's National TB Elimination Programme (NTEP) now prefer daily fixed-dose combinations (FDCs) under DOTS over intermittent therapy. Category II with Streptomycin is being phased out in favour of DST (drug susceptibility test)-guided individualised regimens for retreatment cases. MDR-TB (resistant to H + R) is managed separately with longer regimens (6-9 or 18-20 months) using second-line drugs.

Diagnostic Tests for TB + CXR Findings

A. DIAGNOSTIC TESTS

1. Sputum Smear Microscopy (ZN Stain / Auramine-Rhodamine)

• First-line, most widely available test
• Shows Acid-Fast Bacilli (AFB) - Ziehl-Neelsen stain turns AFB red on blue background
• Sensitivity: 40-60% (poor in smear-negative TB, HIV co-infection, children)
• Requires 3 samples (early morning preferred)
• A positive smear = infectious case - high epidemiological importance

2. Sputum Culture (Gold Standard)

• Lowenstein-Jensen (LJ) medium (solid) - results in 4-8 weeks
• MGIT (Mycobacteria Growth Indicator Tube) liquid medium - results in 1-3 weeks
• Most sensitive and specific test
• Allows drug susceptibility testing (DST)
• Definitive confirmation of active TB

3. CBNAAT / GeneXpert MTB/RIF (Molecular - WHO Recommended First Test)

• Cartridge-Based Nucleic Acid Amplification Test
• Simultaneously detects M. tuberculosis AND rifampicin resistance (proxy for MDR-TB)
• Results in 2 hours
• Sensitivity ~88% (smear positive), ~67% (smear negative)
• Now recommended by WHO as the initial diagnostic test where available
• Very useful in children, HIV co-infected, extrapulmonary TB

4. Tuberculin Skin Test / Mantoux Test (TST)

• Intradermal injection of 5 TU of PPD on volar aspect of forearm
• Read at 48-72 hours - measure induration (not redness) in mm
• Interpretation:
  • ≥5 mm: HIV+, recent TB contact, immunosuppressed
  • ≥10 mm: High-risk groups (healthcare workers, immigrants, diabetics)
  • ≥15 mm: Low-risk individuals
• Limitations: False positive with BCG vaccination & NTM infections; false negative in immunosuppressed, miliary TB, severe malnutrition
• Tests infection, not necessarily active disease

5. IGRA - Interferon Gamma Release Assay (QuantiFERON-TB Gold / T-SPOT.TB)

• Measures IFN-γ release by T cells in response to TB-specific antigens (ESAT-6, CFP-10)
• More specific than TST - not affected by BCG vaccination
• Useful in BCG-vaccinated populations, HIV patients, children
• Cannot distinguish latent TB from active TB
• QFT-Plus is the latest version with improved sensitivity

6. New TB-Specific Skin Tests (TBSTs)

• Uses same ESAT-6/CFP-10 antigens as IGRA but administered like Mantoux
• Combines simplicity of TST + specificity of IGRA
• WHO has assessed accuracy as similar to IGRA, superior to TST

7. Bronchoscopy + BAL (Bronchoalveolar Lavage)

• For smear-negative patients unable to produce sputum
• BAL sent for AFB smear, culture, GeneXpert
• Also useful for endobronchial TB

8. Biopsy (Lymph node, Pleural, Bone, Liver)

• Caseating granuloma with Langhans giant cells = histological hallmark
• Used for extrapulmonary TB diagnosis

9. Adenosine Deaminase (ADA)

• Elevated in TB pleural effusion (>40 U/L), TB meningitis, TB peritonitis
• Simple, cheap, supportive test

10. Blood Tests (Supportive)

• ESR - elevated (non-specific)
• CBC - lymphocytosis, anaemia of chronic disease
• LFT - baseline before treatment (INH hepatotoxicity risk)
• HIV test - mandatory in all TB patients

B. CHEST X-RAY (CXR) FINDINGS IN TB

Primary TB (Children / First Infection)

Primary TB: Right lower lobe consolidation (arrow) + right hilar lymphadenopathy (arrowhead) + right paratracheal adenopathy

• Ghon focus - small parenchymal opacity (mid/lower zone)
• Ghon complex = Ghon focus + ipsilateral hilar lymphadenopathy
• Hilar / paratracheal lymphadenopathy - hallmark of primary TB
• Enlarged nodes can compress bronchi → collapse/consolidation or ball-valve hyperinflation
• Pleural effusion (especially in adolescents/young adults)
• Miliary pattern if disseminated (see below)

Post-Primary / Reactivation TB (Adults)

Reactivation TB: Extensive right upper lobe cavitation

Active TB: Right upper lobe infiltrate + cavity with air-fluid level

Miliary TB

• Bilateral fine 1-3 mm millet-seed nodules uniformly distributed throughout both lungs
• Results from haematogenous dissemination
• Seen in immunocompromised, young children, HIV patients

TB in HIV Co-infection

Paediatric note: CXR findings in children with TB are often subtle. Hilar adenopathy may be the only finding. Sputum smear is often negative in children - gastric lavage or induced sputum + GeneXpert are preferred diagnostic approaches.

CXR Findings in TB (5 Key Points)

Bonus: Healed TB leaves calcification + fibrosis + upper lobe volume loss (tracheal deviation toward affected side). In HIV with low CD4, cavitation is absent and lower zone diffuse opacities predominate.

5 Main Causes of Wheezing

1. Asthma

2. COPD (Chronic Obstructive Pulmonary Disease)

3. Acute Bronchiolitis / Bronchitis

• Bronchiolitis - most common cause of wheeze in infants <2 years, usually due to RSV. Causes inflammation and oedema of small airways with widespread expiratory wheeze and hyperinflation.
• Acute bronchitis - proximal airway inflammation, typically viral, causing transient wheeze with cough in older children and adults.

4. Cardiac Failure / Pulmonary Oedema ("Cardiac Asthma")

5. Foreign Body Aspiration / Airway Obstruction

Other causes to keep in mind: Pulmonary embolism, bronchiectasis, anaphylaxis, vocal cord dysfunction (PVCM - mimics asthma, produces inspiratory stridor more than wheeze), and sarcoidosis.

5 Main Causes of Wheezing in Paediatrics

Key rule from Tintinalli's: Age is the most important guide to the likely cause.

• < 1 year → Bronchiolitis most common
• 1-2 years → Mixed (either possible)
• > 2 years → Asthma most common

1. Bronchiolitis (Infants < 2 years - Most Common in This Age)

• Caused predominantly by RSV (also rhinovirus, human metapneumovirus, parainfluenza)
• Inflammation and oedema of small bronchioles → widespread bilateral expiratory wheeze + hyperinflation
• Preceded by URTI symptoms (nasal congestion, poor feeding, low-grade fever)
• First episode, age <1 year, sick contact during viral season = classic bronchiolitis picture
• Infants are particularly vulnerable due to smaller, more collapsible airways

2. Asthma (Most Common in Children > 2 years)

• Recurrent, episodic wheeze with identifiable triggers (allergens, viral URTI, exercise, cold air)
• Positive family history of atopy / wheeze makes asthma more likely
• Responds to bronchodilators - this is a key diagnostic clue
• Worse at night; symptom-free intervals between episodes
• ~50% of children have a history of wheezing by age 6

3. Foreign Body Aspiration

• Classic in toddlers (6 months - 4 years)
• Sudden onset wheeze after a choking/gagging episode - no preceding URTI
• Typically unilateral / focal wheeze (rather than diffuse bilateral)
• Ball-valve effect → ipsilateral hyperinflation on CXR, mediastinal shift away
• History of playing with small objects or eating nuts/seeds is key

4. Viral-Induced Wheeze / Recurrent Virus-Associated Wheeze

• Distinct from asthma in preschool children (age 1-5 years)
• Wheeze occurs only during viral URTI episodes with no interval symptoms
• No atopy, no triggers between illnesses
• Often resolves by school age
• Related to transient airway hyperresponsiveness post-viral infection

5. Pneumonia / Lower Respiratory Tract Infection

• Bacterial or viral pneumonia can cause wheeze, especially in younger children
• Associated with fever, tachypnoea, chest indrawing, focal crackles
• Wheeze here is due to airway inflammation and secretions, not bronchospasm
• Does not respond well to bronchodilators - key distinguishing feature from asthma

Other Important Paediatric Causes to Exclude

Atypical Pneumonia

What is it?

• Are not visualised on routine Gram stain or ZN stain
• Cannot be cultured on standard media
• Are resistant to beta-lactam antibiotics (penicillins, cephalosporins)
• Produce a milder, more insidious clinical picture than "typical" bacterial pneumonia

Typical vs. Atypical Pneumonia - Key Differences

Causative Organisms

Mycoplasma pneumoniae is by far the most common - accounts for up to 15% of outpatient CAP cases and is the leading cause of atypical pneumonia in school-age children and young adults.

Drug of Choice

In Paediatrics Specifically:

• Azithromycin is the drug of choice for Mycoplasma and Chlamydia pneumonia in children
• Doxycycline is avoided in children <8 years (tooth discolouration)
• Fluoroquinolones are generally not used in young children

Key exam point: Atypical pneumonia = dry cough + extrapulmonary features + normal WBC + patchy CXR + no response to penicillin → treat with Azithromycin (macrolide)

IMNCI Classification of Pneumonia

A. Child Aged 2 Months to 5 Years

I. Very Severe Disease

• Not able to drink
• Convulsions
• Abnormally sleepy or difficult to wake
• Stridor in a calm child
• Severe malnutrition

II. Severe Pneumonia

• Chest indrawing (lower chest wall goes IN on inspiration)
• ± Fast breathing may or may not be present (exhausted child may have slow breathing but still has indrawing)

A child with chest indrawing is at higher risk of death than a child with fast breathing alone.

III. Pneumonia (Not Severe)

• Fast breathing only - no chest indrawing, no danger signs

IV. No Pneumonia: Cough or Cold

• No fast breathing
• No chest indrawing
• No danger signs

B. Young Infant (Birth to 2 Months)

I. Very Severe Disease

• Stopped feeding well (takes <½ usual amount)
• Convulsions / abnormally sleepy / difficult to wake
• Stridor in calm child
• Wheezing
• Fever (≥38°C) OR low body temperature (hypothermia)

II. Severe Pneumonia

• Severe chest indrawing, OR
• Fast breathing (≥60/min)

Note: In young infants, mild chest indrawing can be normal (soft chest wall). Only severe chest indrawing is significant.

III. No Pneumonia: Cough or Cold

• No severe chest indrawing
• No fast breathing (<60/min)

Summary Table