Black piedra: report of a French case associated with Trichosporon asahii

Black piedra: report of a French case associated with Trichosporon asahii Piedra (“stone” in Spanish), also known as trichomycosis nodularis, is an asymptomatic superficial fungal infection of the hair, two varieties of which exist. White piedra (WP) is caused by yeast-like fungi of the Trichosporon genus, and is usually encountered in temperate climates of South America, Europe, Asia, Japan, and the USA. It mostly affects pubic and axillary hair, beards, moustaches, eyebrows, and eyelashes, with scalp hair being less commonly affected. It manifests with white to light-brown soft nodules that are irregularly spaced and loosely attached to the hair shaft. Black piedra (BP), caused by the ascomycete Piedraia hortae, is rarer than WP; it is mainly encountered in tropical climates of South America and Asia, and manifests with small, hard, brown–black nodules firmly attached to the hair shaft, giving it a “gritty” aspect. We report a French patient presenting with clinical and microscopic features of BP, in whom cultures showed the presence of Trichosporon asahii. A 27-year-old man living in French Guyana, in good general condition, consulted for small, hard, black beads firmly attached to the hair shaft that had been present for a few months (Fig. 1). They were predominant on the frontal–parietal hair, but were also present on the posterior scalp, causing cosmetic discomfort only. Pubic and axillary hairs were unaffected. Ketoconazole shampoo had proved to be ineffective. Microscopic examination of the affected hairs before and after lactophenol treatment showed several dark concretions of varying size along the hair shaft; the smaller ones consisted of round spherical elements stuck onto the hair cuticle, and the