BACKGROUNDSuperficial mycoses are fungal infections limited to the outermost layers of the skin. Dermatophytic filamentous fungi and yeasts are the major causative agents of these mycoses. Dermatophytosis is one of the clinical conditions caused by fungal infections most commonly found in dermatological practice. Thus, knowledge of the ecology of dermatophytes provides a better understanding of the natural history of dermatophytosis. OBJECTIVEThis study aimed to investigate epidemiological and mycological features of superficial mycoses diagnosed from 2005 to 2011 in the Dermatology Clinic of the Hospital do Servidor Público Municipal de São Paulo, Brazil. METHODThis retrospective study was conducted in the Laboratory of Medical Mycology at the Dermatology Clinic of the Hospital do Servidor Público Municipal de São Paulo. Mycological examinations of 9042 patients with clinical suspicion of superficial mycoses performed between 2005 and 2011 were reviewed. RESULTSOf 9042 direct microscopic examinations, 2626 (29%) were positive for dermatophytes, 205 (2.3%) were positive for Malassezia, 191 (2.1%) were positive for other types of yeast, 48 (0.5%) were positive for bacteria, and 5972 (66%) were negative. Mean age of patients was 48 years, 6920 (77%) patients were female and 2112 (23%) were male. CONCLUSIONThe biota consisted of six dermatophyte species: T. rubrum, T. mentagrophytes, M. gypseum, T. tonsurans, E. floccosum, and M. canis. The most common site of involvement was the nail and foot in adults and scalp in children, with a female predominance. Both Candida and Malassezia were more prevalent in adult women, the former most commonly affecting the interdigital region and nails and the latter the chest and neck.

Mycological examination is still the cornerstone for the diagnosis of onychomycosis for many dermatologists, but sampling technique interferes on its sensitivity and specificity. Nail abrasion may be used to reach the most proximal part of the lesion and can be easily accomplished with an electric abrasor. We suggest nail plate dermoscopy to identify the best location for localized abrasion to obtain adequate samples for mycological examination.