According to Stokes law by absorption of photons from emitting radiation longer wave length radiation, fluorescence, is stimulated. The phenomenon of fluorescence resembles others such as phosphorescence, chemi-, tribo-, electro-, lyo-, bioluminescence. In dermatology it is used since 1925, Wood’s lamp was discovered in 1903. There exists primary fluorescence of the healthy skin as well as many pathological processes which are listed in tables and attention is drawn to some less commonly used diagnostic possibilities. Frequently also secondary fluorescence is used, i.e. various (incl. intravital) fluorochromes (most frequently fluorescein). This makes possible e.g. the diagnosis of scabies, pigment affections (vitiligo), some contact allergens. There is wide use of immunofluorescent laboratory and microscopic methods. Last but not least, fluorescence is used for detection of drugs, in particular antibiotics (tetracycline, doxycycline) and other chemical substances (dihydroxyacetone). Fluorescence is used also to check the use of preventive preparations for skin protection. It is undergoing brisk development in the therapeutic and diagnostic application of photodynamically active substances in particular porphyrin derivatives. New highly sensitive optoelectronic elements make it possible to introduce spectrofluorimeters into practice.

        Key words: skin fluorescence - Wood’s lamp - primary and secondary fluorescence - application of fluorescence - photodynamic diagnosis and therapy - assessment and recording of fluorescence - bioluminescence