Acne Vulgaris — SCE Dermatology MCQ

Correct answer: E — Oral Isotretinoin

A) Oral Isotretinoin is correct. This 15-year-old has severe nodulocystic acne with scarring that has failed adequate courses of combined oral antibiotics plus topical therapy, which is precisely the NICE-defined threshold for escalation to systemic retinoid therapy. Isotretinoin normalises follicular keratinisation, markedly reduces sebum production, and has anti-inflammatory and anti-Cutibacterium acnes effects, making it the only option that addresses the underlying pathophysiology at this severity. NICE NG198 states that oral isotretinoin should be considered for people over 12 years with severe acne resistant to adequate systemic antibiotic and topical therapy, particularly where scarring risk is present, and specifies it should not be used until such standard therapy has already failed, exactly as described here. Given the established scarring, further delay with less potent agents is inappropriate and specialist-initiated isotretinoin is the definitive next step. Why the other options are wrong: B) Oral Dapsone: Not a recognised NICE or BAD first- or next-line agent for nodulocystic acne; it is reserved largely for neutrophilic dermatoses and does not address sebaceous gland activity or comedogenesis. C) Intralesional triamcinolone: Useful for individual inflamed nodules or early scars but has no systemic effect on widespread nodulocystic disease across the face and trunk, so it cannot control ongoing active disease. D) Oral Ciclosporin: An immunosuppressant with no established role in acne; it does not target sebum production or follicular hyperkeratinisation and carries nephrotoxicity risk disproportionate to benefit here. B. Higher dose oral tetracycline: The patient has already failed adequate antibiotic courses, so simply increasing dose risks resistance and further delays effective treatment without a plausible mechanism to overcome the treatment failure. Key point: Failure of adequate combined oral antibiotic and topical therapy in severe scarring nodulocystic acne is the defining NICE criterion for moving to oral isotretinoin.

Reference: NICE Guideline NG198, Acne vulgaris: management (2021), recommendation 1.5.18, Oral isotretinoin treatment, https://www.nice.org.uk/guidance/ng198/chapter/recommendations