Pharyngitis, tonsillitis, peritonsillar abscess and deep neck infection — branching viva

Opening

Examiner: A 7-year-old presents with two days of sore throat, fever of 38.5 degrees Celsius, enlarged exudative tonsils, tender anterior cervical nodes, and no cough or rhinorrhoea. How do you approach this? ^[1]

Candidate: This is acute pharyngitis with features suggestive of group A streptococcal tonsillitis. My first step is to apply the McIsaac score: fever (1), absence of cough (1), tender anterior cervical nodes (1), tonsillar exudate (1), and age three to fourteen years (1) — a score of 5 out of 5, indicating a high pre-test probability of GAS. The IDSA mandates microbiological confirmation before treating, so I would take a throat swab or rapid antigen detection test and treat only if GAS is confirmed. In the meantime, I would give analgesia: paracetamol 15 mg/kg orally every four to six hours. ^{[1] [2]}

Branch 1 — the antibiotic decision

Examiner: The rapid antigen test is positive for GAS. What do you prescribe? ^[1]

Candidate: First-line therapy for confirmed GAS pharyngitis is phenoxymethylpenicillin (penicillin V) orally for ten days. For his weight, which at seven years is likely over 10 kg, I would give 500 mg orally twice daily for ten days. An equivalent alternative is amoxicillin 50 mg/kg (maximum 1 g) orally once daily for ten days, which is preferred by many families for its once-daily dosing. No GAS strain has ever shown penicillin resistance, so penicillin V remains first-line. ^[1]

Examiner (probe): He has a non-anaphylactic penicillin allergy. What now? ^[1]