Tinea faciei caused by Trichophyton mentagrophytes (molecular type Arthroderma benhamiae ) mimics impetigo : a case report and literature review of cases in Japan.

A 36-year-old female elementary schoolteacher presented with aggregated serous papules surrounded by mild erythema, extending from both nasal wings/nostrils down to the upper lip. No improvement was seen following treatment of the lesions with topical antibiotics for impetigo. Potassium hydroxide (KOH) direct microscopy confirmed the presence of mycelia, and the infection was diagnosed as tinea faciei. The isolate was identified as Trichophyton mentagrophytes using morphological analysis and as Arthroderma benhamiae using genetic analysis. Here we describe that case and summarize the clinical features of other cases of A. benhamiae infection in Japan that have been reported in the literature.