[The risks of photochemotherapy (author's transl)]

The side effect of phototherapy with 8-methoxypsoralen was divided in short- and longterm damage. From 1969 till 1980 2 013 patients were treated. The pattern of alteration by PUVA depends on doses, continuance of therapy and type of dermatoses as psoriasis, vitiligo, mycosis fungoides, physical urticarias, chronic eczemas. The spontaneous development of tumors, the initiating or promotion of tumors by PUVA as well as a regression of tumors by PUVA has to be taken into account regarding the absolute numbers of tumors after PUVA-therapy. The risk of the PUVA-therapy depends on the doses of continuance of the treatment including the combination with other sources of radiations or natural sun-exposition. The possibilities of drug combinations to lower the total doses of light energy are discussed according the recommendation of several teams in Germany.