Non-dermatophyte moulds as pathogens of onychomycosis.

OBJECTIVE To determine the role and pattern of non-dermatophyte moulds as causative agents of onychomycosis. STUDY DESIGN Case series. PLACE AND DURATION OF STUDY Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from November 2009 to July 2010. METHODOLOGY Nail clippings and nail scrapings were obtained from abnormal looking nails with treatment and detection failure for onychomycosis. Microscopic (40% potassium hydroxide mounts) examination and culture on Sabouraud's dextrose agar (SDA), SDA containing chloramphenicol, and SDA containing actidione and chloramphenicol were used for species identification. RESULTS Non-dermatophyte moulds were isolated from 32 out of the total 47 culture positive cases (68%). Alternaria alternata was the commonest species (46%). Dermatophytes were isolated from only 7 patients (15%) belonging to genus Trichophyton. Yeasts were isolated in 8 (17%). There was no fungal growth in 53% of cases. CONCLUSION The non-dermatophytes should be considered important in evaluating the culture negative cases for dermatophytes as well as those cases ending up in treatment failure after empirical treatment for dermatophyte infections.