Inflammatory tinea capitis mimicking dissecting cellulitis in a postpubertal male: a case report and review of the literature.

Tinea capitis in postpubertal patients is unusual and may be misdiagnosed as dissecting cellulitis. We report a case of a healthy 19-year-old Hispanic male presenting with a 2-month history of a large, painful subcutaneous boggy plaque on the scalp with patchy alopecia, erythematous papules, cysts and pustules. Although initially diagnosed as dissecting cellulitis, potassium hydroxide evaluation (KOH preparation) of the hair from the affected region was positive. A punch biopsy of the scalp demonstrated endothrix consistent with tinea capitis, but with a brisk, deep mixed inflammatory infiltrate as can be seen with chronic dissecting cellulitis. Fungal culture revealed Trichophyton tonsurans, and a diagnosis of inflammatory tinea capitis was made. The patient was treated over the course of 17 months with multiple systemic and topical antifungal medications, with slow, but demonstrable clinical and histopathological improvement. A rare diagnosis in adults, clinicians should have a high index of suspicion for this condition in an adult with an inflammatory scalp disorder not classic for dissecting cellulitis or with a recalcitrant dissecting cellulitis. Prompt, appropriate diagnosis and treatment is necessary to prevent the long-term complications of scarring alopecia.