Study of onychomycosis in Isfahan, Iran.

A mycological study was undertaken in 488 patients suspected of onychomycosis in Isfahan, a large province of Iran, to gain more insight into the prevalence and aetiology of this infection. Direct microscopy of the nail clips was positive in 194 (39.8%) and fingernail onychomycosis was recognised in 141 (72.7%) and toenail onychomycosis in 53 (27.3%) cases. As agents of onychomycosis, yeast were detected in 112 (57.7%), dermatophytes in 27 (13.9%) and non-dermatophyte fungi in 55 (28.4%) patients. Of the samples cultured, Candida albicans was the most prevalent (84%) yeast. Among dermatophytes, Trichophyton mentagrophytes var. interdigitale was found to be the commonest aetiological agent (8.6%) followed by Epidermophyton floccosum and T. rubrum. Among the non-dermatophyte moulds, Aspergillus flavus was the most prevalent species (13%). Moreover, nine samples with positive direct microscopy yielded no growth. Females were affected more frequently with fingernail candidal infections than males, and children under 7 years of age were predominantly involved with candidal paronychia. The majority of fungal nail infections were characterised clinically by distal and proximal subungual onychomycosis. The growing trend towards the frequency of fingernail onychomycosis in housewives was noticeable in the last decade in Iran.