INCREASING FREQUENCY OF ONYCHOMYCOSES - I S THERE A CHANGE IN THE SPECTRUM OF INFECTIOUS AGENTS

The recently developed antifungal drugs are not equally effective agai nst the fungi causing onychomycoses: dermatophytes, yeasts and non-der matophyte filamentous fungi (NDFF). Therapeutic failures may be due to the use of antifungal agents not primarily effective against the part icular fungus. Considering the high costs of systemic antifungal thera py, it is necessary to know the frequency distribution of the differen t fungi causing onychomycosis, In a retrospective study, we have analy sed results of fungal cultures performed between 1974 and 1994. In par ticular, we have compared the time periods 1982-1984 and 1992-1994. Cu lture results from toe nails showed in 1982-1984 the following fungal pattern (n = 833): dermatophytes 61%, yeasts 15%, NDFF 17%, mixed infe ctions 7%. Results from 1992-1994 (n = 930) revealed an increase of de rmatophytes 86% at the expense of yeasts (7%), NDFF (3%) and mixed inf ections (3%). In finger nails, we found a more pronounced change of in fectious agents from 1982-1984 (n = 509; dermatophytes 62%, yeasts 29% , NDFF 1%, mixed infections 7%) to 1992-1994 (n = 348; dermatophytes 4 5%, yeasts 52%, NDFF 0,3%, mixed infections 3%). The high rate of yeas t isolations (52%) from finger nails in 1992-1994 is striking. The rol e of yeast isolates for pathogenesis of onychomycosis remains to be el ucidated. Differentiation between colonisation and infection would be necessary. The effectiveness of oral antifungal drugs against dermatop hytic nail infections is well documented. The effectiveness against ye asts and NDFF, however, has not been studied thoroughly, but is not su pposed to be equal with the different antifungal agents. Determination of the infectious agents in onychomycoses is recommended in order to avoid therapeutic failures.