8-METHOXYPSORALEN-A Short Review and Comment.

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 sunlight, including tanning. When too much drug is taken or when the patient is exposed to sunlight too long, the preliminary erythema may be painful, and blistering may occur. In some patients with vitiligo, islands of pigmentation appear around the hair follicles when the drug is taken, and in favorable cases these islands may coalesce to form continuous areas of pigmented skin. The drug has been found nontoxic, but successful treatment of vitiligo takes place in only a small proportion of patients. Promiscuous use of the drug for cosmetic tanning is to be deplored. The constant irritation of the skin due to the increased action of sunlight when the drug is used may possibly increase the incidence of sun-induced skin cancers.A topical preparation is available, which, when used with great care, may help to repigment small areas of vitiligo.