Effects of cyclosporin A on hair.

Cyclosporin A (CSA) is an immunosuppressive agent that has provided new approaches in transplantation medicine and in the treatment of autoimmune diseases. One of the most common dermatological side effects of oral CSA is dose-dependent hypertrichosis. This stimulating effect on hair growth encouraged a number of investigators to use CSA not only in the treatment of alopecia areata (AA), but also in male pattern alopecia (MPA). While oral application proved successful, the beneficial effect of topical application was very limited in both AA and MPA.