Topical minoxidil in extensive alopecia areata, including 3-year follow-up.

Perhaps the most intriguing aspect of topical minoxidil is the fact that this drug can promote hair growth in two unrelated conditions: alopecia areata (AA) and androgenetic alopecia. The two conditions have quite different underlying mechanisms. In AA, hair follicles respond to some signal or cell injury by entering a state of aborted cyclical activity; this state can reverse itself spontaneously, or it can be temporarily circumvented with nonspecific immunomodulating agents. In androgenetic alopecia, genetically marked hair follicles undergo progressive, androgen-mediated miniaturization; antiandrogens have been conventionally sought to intercept this process. It is not known how minoxidil promotes hair growth except that living follicles capable of stimulation and hypertrophy are required. It may be that minoxidil influences some fundamental signal to the follicular apparatus, irrespective of the pathophysiology involved. We have used topical minoxidil solution in 90 patients, aged 7-63 years, with extensive AA affecting 25-100% of the scalp. One study was double-blind, and placebo-controlled for an entire year. Minoxidil-treated patients responded better than placebo-treated patients. Both 3 and 5% topical minoxidil solutions have been used, and treatment with the 3% solution has continued for up to 3 years. The results of these studies will be discussed. While topical minoxidil is not very effective for those with 100% scalp hair loss, it is an effective, easy and safe treatment for those with AA affecting 25-99% of the scalp.