[Onychomycosis due to trichosporon asahii]

ABSTRACT

Trichosporon, saprophyte yeast of the skin and the digestive tract, is responsible at the man's of superficial damage whose white piedra is the most known. Occasionally, Trichosporon may affect the nail. It is reported a rare case of onychomycosis caused by Trichosporon asahii diagnosed in an immunocompetent patient. A immunocompetent 65-year-old patient presents a partial dystrophy ungueale of the big toe with an infringement under - ungueale distale less pronounced besides toenails. The mycological examinations of the material taken on 2 occasions and cultivated on 2 series of middles Sabouraud with or without actidione let push pure colonies evoking Trichosporon. On poor environments potato-carrot-bile, this yeast gave arthrospores, pseudofilaments and characteristic blasospores. The study of assimilation of sugars has concluded a Trichosporon asahii. The implication of Trichosporon asahii as causal agent of onychomycoses is difficult to confirm due to the nature of the saprophytic yeast especially in immunocompetent. However its purely repeated isolation on a series of middles associated with a positive direct examination proof of its pathogenicity. The possible bad local vascular circulatory associated with the microtraumatism and the conditions marked by humidity could explain this passage from the saprophytic to the pathogenic condition. Seen the increase of the number of saprophytes germs that acquire a possible potential pathogenic also to the immunocompetent subjects. We insist on the necessity of multiplying the prelevements and of making a rigorous interpretation of the data of the mycological examination