The possible influence of oxidative stress is discussed in the pathogenesis of polymorphous light eruption (PLE), A double-blind, placebo-controlled study of prophylactic treatment with systemic administration of vitamin C (3 g/d) and E (1500 IU/d) for 8 days was undertaken in 9 patients with PLE (verum, n=4; placebo, n=5), Evaluation of the maximal effects after photoprovocation before and after intake of the antioxidants revealed a reduction of most skin reactions (overall skin reaction, papules/vesicles) in both groups with marked differences in the placebo group. The antioxidants in the doses gi, en and over the time period used did not influence the development of PLE, but might interfere with immunosuppressive effects of repeated photoprovocation tests.