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Hereditary angioedema — SCE Acute Medicine MCQ

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HardAcute Rheumatological/Dermatological EmergenciesHereditary angioedemaSCE Acute Medicine

A 35-year-old man presents with recurrent abdominal pain, vomiting and swelling of the lips. He has no urticaria or wheeze, and previous episodes did not respond to antihistamines or adrenaline. His father had similar attacks. What is the most likely underlying mechanism?

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Correct answer: A — Bradykinin-mediated angioedema from C1 inhibitor deficiency

Recurrent angioedema without urticaria, abdominal attacks and family history suggest hereditary angioedema due to C1 inhibitor deficiency, mediated by bradykinin. IgE-mediated reactions usually have urticaria, itching or bronchospasm and respond to adrenaline. Chronic urticaria is histaminergic and typically itchy. Laryngeal involvement can be fatal, so specific C1 inhibitor or bradykinin-pathway treatment may be required.

Reference: BSACI hereditary angioedema guideline, BNF