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]

Candidate: For a non-anaphylactic penicillin allergy, I would use cephalexin 40 mg/kg/day (maximum 2 g/day) orally in two divided doses for ten days. For a true anaphylactic penicillin allergy, I would switch to clindamycin 21 mg/kg/day (maximum 1.8 g/day) in three divided doses for ten days, or a macrolide such as azithromycin for five days, noting that macrolide resistance exists in some GAS strains and local guidance should be checked. [1]

Branch 2 — the peritonsillar abscess

Examiner: A different child: a 12-year-old with three days of sore throat now has worsening right-sided pain, cannot fully open his mouth, and his voice sounds muffled. On examination the right tonsil is pushed forwards and the uvula is deviated to the left. What is this and what do you do? [4]

Candidate: This is a peritonsillar abscess (quinsy). The classic features are trismus (difficulty opening the mouth), a muffled hot-potato voice, asymmetric tonsillar swelling pushing the tonsil medially, and uvular deviation to the contralateral side. The definitive treatment is drainage — needle aspiration or incision and drainage — performed by a clinician experienced in the technique, combined with antibiotics covering GAS and oral anaerobes, such as amoxicillin-clavulanate or penicillin V plus metronidazole. I would involve ENT for the drainage, ensure he is hydrated (he may need IV fluids if he cannot swallow), and arrange follow-up to confirm resolution. [4]

Branch 3 — the deep neck infection

Examiner (probe): Now a 3-year-old with fever, neck stiffness, drooling and a toxic appearance. How does your approach change? [4]

Candidate: This is a deep neck space infection — most likely a retropharyngeal abscess given the toddler age and the neck stiffness. The approach changes fundamentally from routine management to an emergency pathway. Airway is the first priority: I would keep her sitting upright, avoid forcing any oropharyngeal examination, and involve anaesthetics and ENT urgently. I would obtain IV access, take blood cultures, start broad-spectrum IV antibiotics (ceftriaxone plus metronidazole, or clindamycin), and arrange urgent contrast CT of the neck to define the collection. Surgical drainage is indicated if the abscess is large (over 2 cm), if there is airway compromise, or if she fails to improve on antibiotics. I would not manage this as simple pharyngitis. [4]

Examiner (probe): What if the neck stiffness had led someone to do a lumbar puncture first? [4]

Candidate: That would be a serious pitfall. The neck stiffness of a retropharyngeal abscess reflects the child splinting against the deep neck collection, not meningeal irritation. Performing a lumbar puncture without first imaging risks precipitating abscess rupture or airway compromise, and it delays the definitive diagnosis. The correct sequence is airway assessment, antibiotics, CT neck, and surgical consultation — not a blind lumbar puncture. [4]

Close

Examiner: Summarise your safe approach to paediatric sore throat in one line. [3]

Candidate: Score with McIsaac, confirm GAS with a swab or rapid antigen test before treating, give ten days of penicillin V or amoxicillin for confirmed GAS, and escalate the child with drooling, trismus or neck stiffness as a peritonsillar or deep neck emergency with airway protection, IV antibiotics, CT neck and surgical drainage. [1] [4] [5]