RESUMEN
Alternaria is a common saprophyte that is not usually pathogenic in humans. Alternarial onychomycosis is very rare and it is difficult to make a diagnosis of onycholycosis by moulds. In Korean literature, clinical findings of onychomycosis by Scopulariopsis brevicaulis, Aspergillus sp., Fusarium sp. were reported. But clinical finding of alternarial onychomycosis has not been reported. We report a probable case of alternarial onychomycosis in a 67-year-old Korean farmer. Some of the infected nails showed paronychia, onychia, loss of nail plate, black discoloration of proximal part of the nail plate and proximal nail folds. And some of them showed combined findings of proximal subungual onychomycosis and distal and lateral subungual onychomycosis. Repeated microscopic findings showing typical macroconidia and brownish hyphae of Alternaria were observed on three consecutive KOH smears with one-week interval. But cultures were not successful. Extraction of nail plates with oral antifungal and antibiotic treatment was only partially effective.