Dermatophytes in northern Finland in 1982-90.

The epidemiology of human dermatophytes was studied in northern Finland in 1982-90. The samples were analysed at the Department of Medical Microbiology, University of Oulu. The total number of samples was 17,822, of which 3185 (18%) were positive. The annual number of samples and positive cultures remained relatively constant. Trichophyton rubrum was the most common species being isolated from 2101 samples (66% of all positive cultures), while Trichophyton mentagrophytes was isolated from 815 samples (26%) and Epidermophyton floccosum from 193 samples (6%). T. verrucosum caused an epidemic among cattle keepers in 1987-90, causing 47 infections. Microsporum canis, T. terrestre and T. violaceum were rare. The same species affected both children and adults. There was a tendency towards a decrease in tinea in the groin and a slight increase in tinea pedis. T. rubrum and T. mentagrophytes occurred most frequently in patients aged 41-45 years and as foot infections. E. floccosum usually affected the toe web and the groin in patients aged 21-25 years, more often infecting men. Fifty-four per cent of all positive samples came from men and 46% from women.