[Polymorphous photodermatosis--photobiologic diagnosis and therapy].

Polymorphous light eruption is an acquired photodermatosis, whose causal factors have not yet been identified. The diagnosis is based on the clinical picture and on histology. During the symptomless periods, photo-testing is the most important technique to confirm the diagnosis, since there are no specific laboratory parameters. Regarding our own patients, typical lesions could be provoked by UVA in 50%, by UVB in 20% and by both in 30%. The majority of the patients can be protected during the summer season by intermittent preventive photo(chemo)therapy.