[Photoprotection by psoralen-UVA therapy: experimental and clinical results (author's transl)].

Studies on minimum erythema doses, histological investigations and quantitative determination of DNA repair synthesis of epidermal cells revealed that a tan induced by the oral administration of 8-methoxy-psoralen (8-MOP) and subsequent UVA irradiation gives protection from the erythemogenic effects of sunlight, diminishes UVA-induced cellular injury in the epidermis and, possibly, also shields DNA from incident UV radiation. In a study of 14 patients with severe polymorphous light dermatosis the 8-MOP-UVA induced tan proved to be a clinically effective sunscreen. The uncontrolled use of this method for UV protection of normal individual is, however, not recommended.