🦷 Chapter 1: Sore Throat (Pharyngitis)

Nelson's Pediatric Symptom-Based Diagnosis | Viral vs GAS pharyngitis · Exudates · Red flags · Peritonsillar abscess · Infectious mononucleosis

🔍 Sore Throat in Children: Key Concepts

🦠 Viral vs Bacterial
Most pharyngitis is viral (rhinovirus, adenovirus, EBV, enterovirus). GAS causes ~15-30% of cases in children 5-15y. Viral clues: cough, rhinorrhea, hoarseness, conjunctivitis.
🧪 GAS Pharyngitis Diagnosis
Sudden sore throat, fever, tonsillar exudates, tender anterior cervical nodes, no cough. RADT + confirmatory culture if negative. Treat to prevent acute rheumatic fever.
💊 Treatment & Prevention
Penicillin/Amoxicillin 10d (or benzathine PCN IM). Prevent ARF if given within 9d. Macrolides if allergy. No effect on post-strep GN.
⚠️ Red Flags & Emergencies
Drooling, stridor, trismus, toxic appearance, muffled voice → epiglottitis, peritonsillar abscess, retropharyngeal abscess, Lemierre syndrome.
🧬 Mononucleosis & Others
EBV: exudative pharyngitis + lymphadenopathy + splenomegaly + fatigue + atypical lymphocytosis. Avoid contact sports. Fusobacterium necrophorum can cause Lemierre (jugular thrombophlebitis).
🚩 Scarlet Fever
GAS with erythrogenic toxin → sandpaper rash, Pastia lines, strawberry tongue. Treat same as GAS pharyngitis.

💡 Key Takeaway: Differentiate viral from GAS pharyngitis using Centor/McIsaac criteria and testing. Never treat viral pharyngitis with antibiotics. Recognize suppurative complications (peritonsillar abscess, retropharyngeal abscess) and Lemierre syndrome early.

🩺 Clinical Approach to Sore Throat: Step-by-Step Algorithm

🔹 Step 1: Triage & Red Flags
• Airway assessment: stridor, drooling, tripod position → EPIGLOTTITIS (do not examine oropharynx; immediate ENT/anesthesia).
• Trismus, muffled voice, unilateral tonsillar swelling → peritonsillar abscess.
• Neck stiffness, toxic appearance, posterior pharyngeal bulge → retropharyngeal abscess.
🔹 Step 2: Differentiate Viral vs GAS pharyngitis
• Viral: rhinorrhea, cough, hoarseness, conjunctivitis, diarrhea, discrete ulcers.
• GAS: sudden onset, fever >38°C, tonsillar exudates, tender anterior cervical nodes, palatal petechiae, strawberry tongue, absence of cough.
• Use McIsaac score (age 3-15, fever, exudates, adenopathy, no cough).
🔹 Step 3: Diagnostic Testing
• Rapid antigen detection test (RADT): high specificity. Negative RADT → back-up culture.
• Throat culture = gold standard for GAS.
• Molecular tests (PCR) highly sensitive but detect carriers.
• Monospot/EBV serology if suspect infectious mononucleosis.
🔹 Step 4: Management & Complications
• GAS: Penicillin V or Amoxicillin 10 days (prevent ARF).
• Symptomatic relief: analgesics, hydration.
• Suppurative: peritonsillar abscess requires drainage + antibiotics.
• Lemierre syndrome (Fusobacterium): CT neck, IV antibiotics (metronidazole + beta-lactam).
🔹 Step 5: When to refer or admit
• Airway compromise, severe dehydration, toxic appearance.
• Peritonsillar/retropharyngeal abscess requiring drainage.
• Lemierre syndrome, suspected rheumatic fever or post-strep GN.