Folliculitis Decalvans — SCE Dermatology MCQ

Correct answer: B — 10-12 weeks

The correct answer is B, 10-12 weeks. Combined oral rifampicin 300 mg BD plus clindamycin 300 mg BD is the standard first-line regimen for folliculitis decalvans, a primary neutrophilic scarring alopecia in which recurrent follicular pustules, boggy tender plaques, tufted hairs and S. aureus growth are the classic discriminating features here. The combination targets S. aureus while pairing rifampicin with clindamycin avoids the rapid resistance that develops with rifampicin monotherapy. Current expert consensus defines a single treatment course as 10 to 12 weeks, after which response is reviewed and, if needed, a further course or maintenance therapy (topical or oral agents such as doxycycline or fusidic acid) is used, since prolonging beyond this adds toxicity and resistance risk without extra benefit. Why the other options are wrong: D. 6 months: exceeds the recognised course length and increases rifampicin-related enzyme induction problems and resistance risk with no added remission benefit. A. 2 weeks: far too short to achieve clinical remission; bacterial load and follicular inflammation would not be adequately suppressed, leading to rapid relapse. C. 12 months: not supported by evidence; efficacy plateaus after one or two 10 to 12 week courses, and prolonged use increases hepatotoxicity and drug interaction burden. E. Indefinitely: never used long-term because rifampicin is a potent CYP3A4 inducer (reducing efficacy of the combined oral contraceptive, warfarin and ciclosporin), and durable control is instead achieved with maintenance agents after a defined course rather than continuous combination therapy. Key point: a single course of rifampicin plus clindamycin for folliculitis decalvans is limited to 10-12 weeks, with a maximum of two courses recommended before switching strategy.

Reference: EADV Task Force on Hair Diseases, Position Statement on Management of Folliculitis Decalvans, Journal of the European Academy of Dermatology and Venereology, 2025: one antibiotic course is defined as 10 weeks of clindamycin with rifampicin, with no more than two courses recommended (https://onlinelibrary.wiley.com/doi/10.1111/jdv.20687); consistent with British Association of Dermatologists patient information leaflet on Folliculitis Decalvans.