Several plant families contain species liable to cause phytophotodermatitis. They include the Umbelliferae of which Ammi majus has been known for centuries and the Rutacea to which Citrus bergamia belongs. Phototoxic plants are also found in, e.g., the Moraceae, Leguminosae, Rosaceae and Compositae
8-Methoxypsoralen is a purified extract of the root ammi majus lynn, which was used in a crude form for centuries in the Middle East in the treatment of various skin diseases. In recent years it has been found that the purified extract, when taken internally, increases all skin responses to