Pathogenic fungi that play an important role in the practice of the dermatologist include dermatophytes, yeast-like fungi and moulds. They cause mycoses of the smooth and hairy skin, mucous membranes and nails. A number of factors predispose to the development of fungal infection: reduced immunity in the course of neoplastic diseases, AIDS and a state of immunosuppression of the organism caused by the use of corticosteroid drugs and cytostatic agents.

Systemic diseases such as diabetes, obesity, as well as hypothyroidism, decreased oestrogen levels in postmenopausal women and excessive sweating predispose to the development of fungal infections. The diagnosis of mycoses should be based not only on the clinical picture, but also on direct mycological examination and culture, because dermatomycoses can mimic many other dermatoses, so the clinical picture alone is often not sufficient to make a correct diagnosis.