[Pathogens and pathogenesis of dermatophytoses].

The principles of taxonomic and systematic classification of dermatophytes are described with an emphasis on the relevance of teleomorphic forms. Special attention is given to their relation to dimorphic fungi and the formation of arthroconidia as a parasitic growth form. The main factors contributing to pathogenicity of dermatophytes are explained, including enzymes (especially keratinases), allergens and leukotaxins. Genetic predisposition and the unspecific (serum factors, polymorphoneutrophilic granulocytes) and specific immunological mechanisms of host defence are differentiated and critically evaluated.