POLYMORPHOUS LIGHT ERUPTION - SOME UNUSUAL REACTIONS IN ULTRAVIOLET LIGHT TEST SITES

[摘要] The appearance of erythematous papules in test sites exposed to hot quartz UV light, in some patients with polymorphous light eruption, is well known. Other unusual reactions in test sites occurred in 4 or 27 patients with polymorphous light eruption. There was persistence of erythema in test sites for 7 months following a single initial exposure to UV light in one patient. In a second patient, erythema persisted in test sites for 6 months, faded, then spontaneously recurred. Chloroquine did not alter this reaction. The significance of this persistent and recurrent erythema is not known. It may represent vascular damage from UV light. In two patients, typical polymorphous light eruption following sunlight exposure was accompanied by the appearance of papules in previously tested sites, which were not re-exposed. Prior intense UV light exposures in the same test areas had resulted in no observable reaction in one case, although a typical papular response was noted in the other case. These unusual papular reactions suggest that polymorphous light eruption is a true photoallergic disease. Chloroquine does not act as a sun filtering agent in patients with polymorphous light eruption, but may act by suppressing the specific photoallergic response.