Beta-carotene as a photoprotective agent in erythropoietic protoporphyria.

Abstract

Three patients with erythropoietic protoporphyria, with elevated levels of porphyrin in blood and stool and with severe photosensitivity on exposure of skin to both sunlight and artificial light were treated with an oral preparation of beta-carotene. After treatment, two of the patients were able to tolerate five to eight hours of sun without experiencing photosensitivity, and the third could tolerate exposure to sun with less discomfort than he had experienced before therapy. When the patients were carotenemic, they also reacted less intensely to artificial light. Beta-carotene appears to counteract photosensitization in the skin of these patients, and carotenoid pigments prevent photosensitization in bacteria, plants and mice. Whether the mechanism of action of carotenes is the same in all cases is not yet known.