fungal nail infections in tehran, iran

background: onychomycosis results from invasion of the nail plate by dermatophytes, yeasts or mould species of fungi. the objective was to determine the etiological agents of onychomycosis. methods: a total of 549 patients clinically suspected of onychomycosis were examined for causative fungal agents. both di­rect microscopy and the cultures of the nail material were performed to identify the causative agents between 2004-2005 in tehran, iran. results: out of 549 cases examined, 263(47.9%) were mycologically proven cases of onychomycosis (139 finger, 124 toe nails), among those 33(6.09%) were only positive in direct microscopic examination. from an etiological point of view, 21.85% of nail infections were caused by yeasts, 10.55% were infected by dermatophytes and 15.5% by non-dermatopyte moulds. candida albicans was the common yeast causative agent (16.73%) followed by a. flavus (11.78%), t. mentagro­phytes (10.26%), c. parapilosis (9.12%), c. tropicalis (8.74%), a. fumigatus (6.08%), t. rubrum (4.94%), a. niger (3.04%), peni­cillium spp. (2.66%), aspergillus spp (1.90%), each of rhizopus spp and cladosporium spp (1.52%), c. guilliermondii (1.14%), sco­po­lariopsis spp. (1.14%), each of c. famata , c. glabrata , c. krusei , s. lusitania , acremonium spp. (0.76%) and c. homicola (0.38%), t. rubrum (4.94%). candida species were most common responsible agent for onychomycosis in fe­male hands (74.1%) fol­lowed by 17.26% non-dermatophyte moulds. dermatophytes caused tinea unguim of hand (8.63%) and peduum (37.1%) in males. onychomycosis of finger nails was most prevalent in females while toenail infection was com­mon in male patients. conclusion: the yeasts of the genus candida and non-dermatophyte moulds are dominant cause of female finger nail onychomy­cosis and dermathophytes are principal cause of both finger and toe nails in males in tehran.