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Pharyngitis: Acute and Chronic

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1. Definition and Classification

• Acute pharyngitis — onset over hours to days; resolves within 3–7 days (infectious majority)
• Chronic pharyngitis — persistent or recurrent inflammation lasting weeks to months; often non-infectious in etiology

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2. Etiology

Acute Pharyngitis

• Rhinovirus, influenza A/B, parainfluenza, adenovirus, coxsackievirus (herpangina, hand-foot-and-mouth), echovirus, RSV
• Epstein-Barr virus (EBV) — infectious mononucleosis
• Herpes simplex virus (HSV) — exudative or non-exudative pharyngitis
• HIV (acute retroviral syndrome)
• Rarely: CMV, measles, rubella

• Streptococcus pyogenes (Group A β-hemolytic Streptococcus, GAS) — most important bacterial cause (20–40% of pediatric cases; 5–15% of adult cases)
• Non-group A β-hemolytic streptococci (Groups B, C, G)
• Neisseria gonorrhoeae — sexually transmitted; often overlooked
• Corynebacterium diphtheriae — membranous pharyngitis; rare in vaccinated populations
• Arcanobacterium haemolyticum — resembles streptococcal pharyngitis with rash in young adults
• Fusobacterium necrophorum — Lemierre syndrome risk
• Mycoplasma pneumoniae, Chlamydophila pneumoniae — atypical organisms

• Fungal (Candida albicans) — immunosuppressed patients
• Parasitic (rare)

Chronic Pharyngitis

• Persistent low-grade infection or recurrent acute episodes
• Laryngopharyngeal reflux (LPR) — a leading non-infectious cause
• Tobacco smoke, alcohol, dry air, occupational irritants, dust
• Chronic mouth breathing (nasal obstruction, deviated septum, adenoid hypertrophy)
• Chronic sinusitis with postnasal drip
• Allergy / vasomotor rhinitis
• Systemic diseases: Sjögren syndrome, sarcoidosis, amyloidosis, pemphigus
• Vitamin A deficiency (contributes to atrophic changes)

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3. Pathogenesis

Acute

• Viral: Direct cytopathic effect on pharyngeal epithelium → mucosal edema, erythema, cellular infiltrate. Many viral infections are transmitted droplet or contact route.
• GAS (Streptococcal): S. pyogenes adheres to pharyngeal epithelium via M protein and other surface adhesins → local invasion → release of streptolysin O, streptolysin S, pyrogenic exotoxins (causing scarlet fever rash), DNase, hyaluronidase → intense local inflammatory response → fever, exudate, lymphadenopathy.
  • Pharyngitis induces antibodies against M protein, streptolysin O, DNase, hyaluronidase, and pyrogenic exotoxins.
  • Non-treated infection may spread suppuratively or trigger immune-mediated sequelae (rheumatic fever, glomerulonephritis).

Chronic

• Repeated acute insults → chronic mucosal edema → lymphoid hyperplasia (hypertrophic/granular form)
• Prolonged irritation (smoke, reflux, dry air) → progressive glandular atrophy, mucosal thinning, decreased mucus secretion → atrophic form
• LPR: Acid and pepsin reach the posterior pharynx → posterior laryngitis, interarytenoid edema, erythematous arytenoids, reactive changes

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4. Clinical Symptoms

Acute Pharyngitis

• EBV mononucleosis: fever, severe malaise, pharyngitis, cervical lymphadenopathy (large and tender), splenomegaly, palatal petechiae, occasional green/gray tonsillar exudate (indistinguishable from GAS)
• Herpangina (Coxsackievirus): vesicles → ulcers on anterior tonsillar pillars, soft palate, posterior pharynx
• Influenza: abrupt fever, headache, myalgias, sore throat, mild pharyngeal hyperemia without exudate
• HIV acute retroviral: fever, diffuse lymphadenopathy, maculopapular rash, pharyngitis (often with ulcerations)

Chronic Pharyngitis

• Persistent throat discomfort, tickling, irritation, or dryness
• Chronic throat-clearing
• Low-grade dysphagia
• Postnasal drip sensation ("globus")

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5. Physical Examination & Diagnostics

Acute Pharyngitis — Oropharyngeal Findings

• Score 0–1: No testing or antibiotics needed
• Score 2–3: Rapid antigen test recommended
• Score ≥ 4: Empiric antibiotics reasonable; culture if rapid test negative

• Rapid antigen detection test (RADT): Sensitivity ~85%; specificity high. If negative in children/adolescents → send throat culture.
• Rapid nucleic acid test (NAAT): Sensitivity 97.5%, specificity 95% — preferred.
• Throat culture: Gold standard. Posterior pharynx/tonsillar surface swab. Treat if positive; no need to culture adults with negative rapid test (low GAS prevalence, low rheumatic fever risk).
• Monospot/heterophile antibody test: EBV mononucleosis screening
• CBC: Atypical lymphocytosis in EBV; leukocytosis in bacterial infection
• ASO titer, anti-DNase B: Retrospective confirmation of GAS infection (used for rheumatic fever / glomerulonephritis workup)

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6. Differential Diagnosis: Chronic Pharyngitis Forms

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7. Treatment

Acute Pharyngitis

• Supportive: analgesics (NSAIDs, acetaminophen), adequate hydration, throat lozenges, warm saline gargles
• Influenza: Neuraminidase inhibitors (oseltamivir 75 mg bid × 5 days, zanamivir) — effective only if started within 48 hours; reduces duration by 1–2.5 days; recommended in high-risk groups
• EBV mononucleosis: Supportive; avoid contact sports (splenomegaly/rupture risk); avoid amoxicillin/ampicillin (causes widespread maculopapular rash in ~90% of EBV patients); corticosteroids for severe airway edema or thrombocytopenia
• HSV: Acyclovir — especially in immunosuppressed patients with chronic herpetic pharyngitis

• Penicillin V 250 mg × 4/day or 500 mg × 2/day × 10 days (antibiotic of choice)
• Amoxicillin 500 mg × 3/day or 875 mg × 2/day × 10 days (often preferred in children — pleasant taste, once-daily dosing studied)

• Azithromycin 500 mg/day × 3 days (Z-pack) — note increasing macrolide resistance
• Clindamycin 300 mg × 4/day × 10 days

• Amoxicillin-clavulanate 875/125 mg × 2/day × 10 days
• Cefuroxime axetil 250 mg × 2/day × 10 days — more effective than penicillin for primary treatment; effective for persistent infection

• Single-dose oral or IM corticosteroid (dexamethasone 10 mg PO/IM × 1) reduces severity and duration of pain — particularly in severe cases and children
• Antibiotics reduce contagion period from ~2 weeks to 24 hours after initiation
• Must begin antibiotics within 10 days of symptom onset to prevent rheumatic fever
• Antibiotics do NOT reduce risk of post-streptococcal glomerulonephritis

• Ceftriaxone 500 mg IM single dose (+ treat for Chlamydia if not tested)

• Fluconazole or nystatin suspension

Chronic Pharyngitis — General Principles

• Eliminate causative factors: smoking cessation, alcohol reduction, humidification, treat nasal obstruction, sinusitis, adenoids
• Treat LPR: dietary modification, elevate head of bed, proton pump inhibitor × 3 months
• Treat allergic disease: antihistamines, intranasal corticosteroids

Chronic Hypertrophic (Granular) Pharyngitis

• Address underlying causes (reflux, allergy, chronic infection)
• Alkaline or saline irrigations/gargles (reduce crusts, thin secretions)
• Topical anti-inflammatory sprays
• Cauterization or laser ablation of discrete granular nodules (in refractory cases)
• Immunotherapy for allergic component

Chronic Atrophic Pharyngitis

• Mucosal hydration: frequent water intake, saline irrigations, humidification
• Vitamin A supplementation (addresses glandular atrophy in deficiency states)
• Alkaline-oil inhalations (olive oil, mineral oil aerosols — lubricate mucosa)
• Treat underlying systemic disease (Sjögren: artificial saliva, pilocarpine; sarcoid: corticosteroids)
• Biostimulants (FIBS, aloe vera — used in Eastern European protocols)
• Avoid further irritants absolutely

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8. Complications

Acute Pharyngitis (especially GAS)

• Peritonsillar abscess (quinsy) — most common local complication; unilateral uvular deviation, "hot potato" voice, trismus
• Retropharyngeal/parapharyngeal abscess — neck stiffness, drooling, airway risk
• Otitis media — spread via Eustachian tube
• Sinusitis — contiguous spread
• Mastoiditis, meningitis, brain abscess (rare)
• Lemierre syndrome (Fusobacterium): septic thrombophlebitis of internal jugular vein
• Bacteremia / septicemia
• Scarlet fever (GAS pyrogenic exotoxin): characteristic rash, strawberry tongue, perioral pallor
• Streptococcal toxic shock syndrome (uncommon)

• Acute Rheumatic Fever (ARF): 2–4 weeks post-pharyngitis; carditis, migratory polyarthritis, Sydenham chorea, erythema marginatum, subcutaneous nodules — prevented by antibiotics within 10 days
• Post-streptococcal glomerulonephritis (PSGN): 1–3 weeks post-pharyngitis; hematuria, proteinuria, edema, hypertension — NOT prevented by antibiotics

EBV Mononucleosis:

• Splenic rupture (avoid contact sports for 3–4 weeks)
• Airway obstruction from massive tonsillar enlargement
• Hemolytic anemia, thrombocytopenia
• Meningoencephalitis (rare)
• Amoxicillin/ampicillin rash

Chronic Pharyngitis:

• Chronic cough, recurrent upper respiratory infections
• Progression to laryngitis, chronic laryngopharyngeal reflux disease
• Sleep-disordered breathing
• Risk marker for malignancy (persistent symptoms warrant laryngoscopy if >4 weeks duration without resolution)

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9. Prevention

• Hand hygiene — primary prevention of spread
• Avoid sharing utensils, glasses
• Respiratory droplet precautions
• Prompt antibiotic treatment shortens infectious period to 24 hours post-initiation
• Influenza vaccination annually — at least 70% effective; recommended for age >50, children 6–24 months, pregnant women, healthcare workers, immunocompromised, residents of long-term care facilities
• Hib vaccine — prevents epiglottitis (not pharyngitis per se, but related)
• Tonsillectomy — reduces frequency of throat infections in patients with recurrent symptomatic GAS episodes despite appropriate antimicrobial therapy (effective short-term)

• Smoking cessation
• Nasal breathing — treat all causes of obstruction
• Adequate indoor humidification (especially in dry/cold climates)
• Treat GERD/LPR proactively
• Occupational protection from dust and chemical irritants
• Avoid excessive voice strain

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• Cummings Otolaryngology Head and Neck Surgery (Chapters 201 and the pharyngitis/laryngitis review chapter)
• Goldman-Cecil Medicine, International Edition (Chapters 269 and 397)
• Tintinalli's Emergency Medicine; ROSEN's Emergency Medicine; Sherris & Ryan's Medical Microbiology