PROXIMAL SUBUNGUAL ONYCHOMYCOSIS DUE TO MICROSPORUM-CANIS

A case of proximal subungual onychomycosis due to Microsporum canis in a 36-year-old woman is presented. The onychomycosis involved the left thumb and the little fingernails, with thinning of the nail plate and crumbling of the nail plate surface. A milky-white discoloration of t he proximal portion of the left thumbnail was also evident. A 2-mm lon gitudinal nail biopsy showed a large number of fungal elements in the whole length of the nail plate. Fungal hyphae were more numerous in th e ventral nail plate and produced detachment of the superficial nail p late. The nail bed was not invaded by fungal elements and was devoid o f inflammatory changes. Proximal subungual onychomycosis is uncommon i n immunocompetent individuals but has frequently been described in pat ients with AIDS. In our patient, in whom the proximal subungual onycho mycosis was due to M. canis, there were no clinical or biochemical sig ns of immunodeficiency. Oral treatment with terbinafine, 250 mg/daily for 2 months, produced clinical and mycological cure.