Oral carotenoids for photohypersensitivity in patients with erythrohepatic protoporphyria, polymorphous light eruptions and lupus erythematodes discoides.

beta-Carotene and canthaxanthin in a dose of 75--250 mg a day by mouth reduced the symptons of exposure to the sun in all 7 treated patients with erythrohepatic protoporphyria (EPP), in 15 of 18 with polymorphous light eruptions (PMLE) and in 3 of 4 with lupus erythematodes discoides. In the EPP group the protoporphyrin level tended to vary inversely with that of the serum carotenoids. The level of retinol-binding protein in plasma remained unchanged despite a substantial rise in the concentration of the serum carotenoids. Estimation of the minimal erythema dose for unfiltered light from a Xenon lamp in 7 patients with PMLE showed an increase in only 1 patient. Neither clinical examination nor repeated laboratory studies revealed any serious side effects of the treatment.