Tinea Capitis — SCE Dermatology MCQ

Correct answer: E — Oral Griseofulvin

Oral Griseofulvin (option C) is correct. The clinical picture (an animal contact with patchy alopecia, an expanding annular facial lesion, and a zoophilic exposure) points to Microsporum canis, and for tinea capitis caused by Microsporum species griseofulvin remains the first-line oral agent in UK practice because it achieves higher mycological cure rates against Microsporum than terbinafine. Griseofulvin is dosed at 15 to 20 mg/kg/day (max per BNFc limits) for 6 to 8 weeks, continued until clinical and mycological cure, reflecting the longer treatment course Microsporum infections typically require compared with Trichophyton tonsurans. Topical therapy alone is inadequate because dermatophytes in tinea capitis invade the hair shaft and follicle, a site topical agents cannot adequately penetrate, so systemic treatment is mandatory once scalp or hair-bearing skin involvement is suspected. Why the other options are wrong: D. No oral treatment needed, topical only: Tinea capitis involves the hair follicle and shaft; topical antifungals cannot penetrate deeply enough to eradicate the organism, so systemic therapy is always required. B. Oral Terbinafine: Terbinafine is first-line for Trichophyton tonsurans infections but has significantly lower efficacy against Microsporum canis, making it a second-line choice here. C. Oral Itraconazole: Itraconazole is an effective alternative but is reserved as second-line or for griseofulvin-refractory or intolerant cases, not first-line for Microsporum in UK guidance. A. Oral Fluconazole: Fluconazole has the weakest evidence base of the systemic antifungals for tinea capitis and is not recommended as first-line therapy for any dermatophyte species in this indication. Key point: For zoophilic Microsporum canis tinea capitis, griseofulvin outperforms terbinafine and remains first-line, whereas terbinafine is preferred for anthropophilic Trichophyton tonsurans infection.

Reference: British Association of Dermatologists / European Society for Paediatric Dermatology guidance on tinea capitis management in children; BNF for Children, Griseofulvin monograph, https://bnfc.nice.org.uk/drugs/griseofulvin/