Acne Vulgaris — SCE Dermatology MCQ

Correct answer: B — Benign intracranial hypertension (pseudotumour cerebri)

The correct answer is B, benign intracranial hypertension (pseudotumour cerebri). Isotretinoin is a recognised cause of raised intracranial pressure without a mass lesion, presenting with headache, papilloedema, and visual disturbance, and the risk rises sharply when combined with tetracycline antibiotics, hence co-prescription is contraindicated in UK practice. The stem's combination of severe headache plus papilloedema in a patient on isotretinoin is the classic clinical picture taught for this drug-specific adverse effect, and immediate isotretinoin withdrawal with urgent ophthalmology/neurology referral is required once suspected. Why the other options are wrong: E. Migraine: Migraine does not cause papilloedema; the presence of papilloedema indicates raised intracranial pressure rather than a primary headache disorder. A. Meningitis: Meningitis typically presents with fever, neck stiffness, and photophobia, and is not a recognised drug-induced complication of isotretinoin; papilloedema may occur but the systemic infective features are absent here. C. Optic neuritis: Optic neuritis causes painful unilateral visual loss with a relative afferent pupillary defect, not papilloedema with headache, and is not an isotretinoin-associated complication. D. Cerebral venous sinus thrombosis: This can cause headache and papilloedema but is not the recognised isotretinoin-specific adverse effect; it lacks the direct causal drug link and would require imaging (MR venogram) to distinguish, whereas benign intracranial hypertension is the well-documented isotretinoin class effect. Key point: Headache and papilloedema in a patient on isotretinoin should always prompt immediate drug discontinuation for suspected benign intracranial hypertension, especially if tetracyclines are co-prescribed.

Reference: The Pharmaceutical Journal (Royal Pharmaceutical Society), 'Isotretinoin use: best practice', 2023: 'Tetracycline antibiotics are contraindicated with isotretinoin owing to the risk of benign intracranial hypertension.' https://pharmaceutical-journal.com/article/ld/isotretinoin-use-best-practice