RESUMO
The isolation and distribution rate of dermatophytes as causative agents of superficial mycoses of skin, hair, and nails during an 18-year period (1991-2008) at a university hospital are presented. A comparative analysis of epidemiological differences within the first (1991-1999) and the second 9-year period (2000-2008) was performed. Skin scrapings, nail, and hair specimens were examined by a direct microscopic examination and culture. Identification of dermatophyte species was based on macroscopic and microscopic characteristics of colonies. During the complete period (18 years), 5,971 patients with suspected dermatophytosis were examined. Seven hundred and sixty-nine patients (12.8%) were found positive. Among them, 495 cases (64.3%) were of skin dermatophytoses, 91(11.8%) of hair, and 183 (23.7%) of nails. The most frequent etiological agents were Microsporum canis (54%), Trichophyton rubrum (38%), and T. mentagrophytes (6%). Epidermophyton floccosum, T. tonsurans, T. violaceum, and M. gypseum were responsible only for 16 cases (2%) of dermatophytoses. The prevalence of dermatophytoses seems to decrease significantly from 16.2% (1991-1999)-9.6% during the last 9-year period. The most frequent dermatophyte, M. canis, shows decreasing trends during the last period (from 58.5 to 45.7%), whereas T. rubrum shows an increasing isolation rate (from 35 to 43.6%), respectively. The most common form of dermatophytosis among children remains tinea capitis due to M. canis. The most frequent etiological agent of tinea unguium (81%) is T. rubrum.
