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Antibiotic-induced anaphylaxis — SCE Acute Medicine MCQ

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HardAcute Rheumatological/Dermatological EmergenciesAntibiotic-induced anaphylaxisSCE Acute Medicine

A 24-year-old woman develops wheeze, facial swelling and collapse five minutes after intravenous co-amoxiclav. BP is 72/40 mmHg, SpO2 89% and there is widespread urticaria. What is the most important immediate action?

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Correct answer: E — Give intramuscular adrenaline 500 micrograms into the anterolateral thigh

This is anaphylaxis with airway, breathing and circulatory compromise, requiring immediate IM adrenaline. Antihistamines and corticosteroids are adjuncts and must not delay adrenaline. Nebulised salbutamol can help bronchospasm but does not treat shock or airway oedema. The correct dose for adults and most teenagers in healthcare settings is 500 micrograms IM of 1 mg/mL adrenaline.

Reference: Resuscitation Council UK anaphylaxis guideline 2021, BNF