Scorpion envenoming — DTM&H MCQ

Correct answer: C — Severe scorpion envenoming

Severe scorpion envenoming (option B) is correct because the vignette describes the classic autonomic storm seen after venom-induced catecholamine and acetylcholine release: intense local pain followed by sweating and vomiting (cholinergic phase), then hypertension and cardiogenic pulmonary oedema (catecholaminergic phase). This pattern, occurring after a scorpion sting in North Africa (where Androctonus and Buthus species cause significant morbidity), is well documented as the mechanism of systemic envenoming, with children being disproportionately affected due to lower venom-to-body-mass ratios producing more severe cardiorespiratory toxicity. Pulmonary oedema in this setting is myocarditis-driven and catecholamine-mediated rather than purely fluid overload, which is why it defines "severe" envenoming requiring urgent antivenom, alpha-blockade and cardiorespiratory support rather than a minor local sting. Why the other options are wrong: A. Snakebite coagulopathy: There is no history of snakebite, and coagulopathy presents with bleeding, bruising and clotting derangement, not the pain-sweating-hypertension-pulmonary oedema sequence described. E. Tetanus: Tetanus causes trismus, muscle rigidity and spasms after a contaminated wound, with a longer incubation period; it does not explain the acute autonomic and cardiovascular features here. D. Heat exhaustion: Heat exhaustion causes hypotension, tachycardia and collapse from volume depletion, not hypertension and pulmonary oedema, and has no direct link to a scorpion sting. B. Anaphylaxis alone: Anaphylaxis produces hypotension, urticaria and bronchospasm from histamine release, not hypertension with pulmonary oedema, and does not account for the venom-specific autonomic sequence. Key point: In scorpion envenoming, sweating and vomiting followed by hypertension and pulmonary oedema represent the biphasic autonomic storm (cholinergic then adrenergic) that defines severe, potentially fatal envenoming, especially in children.

Reference: WHO Eastern Mediterranean Regional Office, Al-Sadoon MK & Jarrar BM, 'Scorpion sting syndrome: epidemiology, clinical presentation and management of 2240 cases', Eastern Mediterranean Health Journal, 1997; https://www.emro.who.int/emhj-volume-3-1997/volume-3-issue-1/article10.html