Arch Dermatol.1984;120:457.

Alopecia areata treated with topical minoxidil.

Weiss VC, et al

edited for hair loss blog

A minoxidil topical solution was used to treat 48 patients with hair loss due to alopecia areata, ie, 24 patients with patchy disease and 24 patients with total hair loss or alopecia universalis. Twenty-five patients had terminal hair regrowth"; in 11 of the 25 patients, it was cosmetically acceptable. No clinical features of the disease seemed to indicate the likelihood of hair regrowth. Hair regrowth began two months after start of treatment and was not uniformly well maintained after the treatment was terminated. One patient had an allergic contact dermatitis reaction to the minoxidil solution; no systemic side effects were seen. No notable systemic absorption was found in 18 adult patients. Effects on cutaneous blood flow or the immune system or some direct effect on hair follicles are possible mechanisms by which minoxidil therapy might stimulate hair regrowth.

...Studies demonstrate that loss of hair follicles involves distinct patterns of expression of active caspases. Active caspase 8, an initiator of the death receptor pathway, was predominately found in the isthmic and upper lower portion of the shaft. This pattern of expression suggests that the death receptor pathway is activated during hair regrowth and is initiated by toxic substances that bind to death receptors, i.e., TNF-alpha. Interestingly, activated caspase 3, a downstream effector caspase, was higher in catagen hair then in other phases of the hair cycle, indicating a role in the terminal stage of the apoptotic pathway. Activated caspase 1 was also found in the hair bulb and hair shaft. This study suggests an important role of the infundibular area of the hair shaft where inner and outer root sheath are abruptly changing and that this area may play a role in the regulation of normal hair apoptosis. Caspase 3 seems to be playing the key role in the apoptotic pathway during the catagen phase of the hair cycle in these areas. Finasteride may exhibit its influence by selectively inhibiting DHT, which affects a multitude of "androgen responsive genes", such as the caspase pathway, which affects programmed cell death in the hair regrwothcycle