Pharyngitis, tonsillitis, peritonsillar abscess and deep neck infection — formative SAQs

SAQ 1 (10 marks)

An 8-year-old boy presents with two days of sore throat, fever to 38.8 degrees Celsius, headache and abdominal pain. He has no cough or rhinorrhoea. On examination his tonsils are enlarged with white-yellow exudate, there are tender enlarged anterior cervical lymph nodes, and the rest of the examination is unremarkable. [1] [2]

1. Calculate his McIsaac score and explain how it guides your next step. (3) [2]
2. Outline your management plan including the antibiotic decision and doses if GAS is confirmed. (4) [1] [3]
3. Describe your safety-net advice and the circumstances under which the family should return urgently. (3) [1]

Model answer — SAQ 1

(1) McIsaac score and next step (3). The McIsaac score components are: fever above 38 degrees Celsius (present, 1 point), absence of cough (present, 1 point), tender anterior cervical lymphadenopathy (present, 1 point), tonsillar swelling or exudate (present, 1 point), and age three to fourteen years (present, 1 point). His total score is 5 out of 5, indicating a high pre-test probability of GAS. The correct next step is a throat swab or rapid antigen detection test — the IDSA mandates microbiological confirmation before treating in children, so I would test and treat if positive, rather than treat empirically on clinical grounds alone. [2] [1]

(2) Management plan (4). First, give analgesia: paracetamol 15 mg/kg orally every four to six hours (maximum 60 mg/kg/day) and encourage oral fluids. If the throat swab or RADT confirms GAS, first-line therapy is phenoxymethylpenicillin (penicillin V) for ten days — for a child of his weight (likely over 10 kg), 500 mg orally twice daily for ten days — or amoxicillin 50 mg/kg (maximum 1 g) orally once daily for ten days. If the test is negative, no antibiotic is needed; this is viral pharyngitis and analgesia with a safety-net suffices. I would not give amoxicillin empirically before the test result, because if he has EBV rather than GAS, amoxicillin would cause a characteristic maculopapular rash and a false penicillin-allergy label. [1] [3]

(3) Safety-net advice (3). Give a concrete, written safety-net: return at any time if his sore throat or fever worsens or does not improve after 48 hours of antibiotics (or after three to four days if untreated), if he develops difficulty swallowing, drooling, neck swelling or stiffness, a muffled voice, or if he simply looks more unwell. These symptoms may indicate a suppurative complication such as peritonsillar or deep neck abscess. Arrange a planned review at 48 to 72 hours if symptoms have not started to improve. Explain that he should complete the full ten-day course even after feeling better, to prevent acute rheumatic fever. [1]

SAQ 2 (10 marks)

A 3-year-old girl presents with four days of fever, sore throat and progressive refusal to drink. Today she is drooling, holding her neck stiff and extended, and refusing to move her head. Her temperature is 39.5 degrees Celsius, she looks toxic, and there is fullness in the right anterior neck. [4] [5]

1. What is the most likely diagnosis, and which complication of throat infection does this represent? (3) [4] [5]
2. Outline your immediate management priorities in the emergency department. (4) [4]
3. Discuss the pitfalls to avoid and the features that distinguish this from uncomplicated pharyngitis. (3) [1] [4]

Model answer — SAQ 2

(1) Diagnosis (3). The most likely diagnosis is a retropharyngeal abscess — a deep neck space infection behind the pharynx. This is a suppurative complication of throat or upper airway infection that has spread to the retropharyngeal lymph nodes (which are prominent in this age group and drain the nasopharynx). The diagnostic features are the toddler age (peak incidence two to four years), toxic appearance, high fever, neck stiffness and hyperextension with refusal to flex (mimicking meningism), drooling from inability to swallow, and neck fullness. The neck stiffness here is not meningism — it is the child splinting against the pain of the deep neck collection. [5] [4]

(2) Immediate priorities (4). This is an emergency. Airway is the first priority: keep her sitting upright and comfortable in a position she chooses, do not force her to lie flat, and do not instrument the oropharynx without airway expertise — forcing examination can precipitate abscess rupture and airway obstruction. Involve anaesthetics and ENT urgently. Obtain intravenous access, take blood cultures and inflammatory markers, and start broad-spectrum intravenous antibiotics covering GAS, oral anaerobes and Staphylococcus aureus — for example ceftriaxone plus metronidazole, or clindamycin. Arrange urgent contrast-enhanced CT of the neck once she is stabilised, to define the collection, its size and the space involved. A collection larger than 2 cm, airway compromise, or failure to improve on antibiotics warrants surgical drainage by ENT. [4]

(3) Pitfalls and distinguishing features (3). The key pitfalls are treating this as uncomplicated pharyngitis with oral antibiotics and outpatient review; attributing the neck stiffness to meningitis and performing a lumbar puncture without imaging (which risks precipitating abscess rupture); forcing a throat examination that precipitates airway obstruction; and delaying CT or ENT involvement. This differs from uncomplicated pharyngitis by the toxicity, the high and persistent fever (four days, getting worse), the drooling and refusal to drink indicating dysphagia, the neck stiffness and hyperextension indicating deep neck involvement, and the palpable neck fullness — none of which are features of simple viral or GAS tonsillitis. The safe approach is early recognition, airway protection, IV antibiotics, CT neck and surgical consultation. [1] [4]