[Photosensitivity induced skin diseases]

The causes of skin diseases associated with photosensitivity are presented. The combined effect of light and exogenous light sensitizing substances leads to the occurrence of phototoxic and photoallergic reactions, and what is more, UVA spectrum is most active in their pathogenesis. The light sensitizing compounds are contained in cosmetic preparations, drugs and certain plants. They are characterized by a tricyclic structure and the ability to absorb ultraviolet radiation. The light sensitizing properties are exhibited primarily by non-steroid anti-inflammatory drugs, preservatives, sun filters, phenothiazine derivatives and odorants. Photoallergic reactions may be of occupational nature. The majority of reports found in the literature concern farmers, gardeners, fruit-growers and breeders, as well as representatives of other occupations. They usually emerge after the contact with pesticides of the thiocarbamide group, tetrachloroisophthalonitryl and veterinary drugs. The cases of occupational eczema in farmers and gardeners induced by the effect of light sensitizing plants have also been reported. In addition, the photoallergy diagnostic methods are discussed.