Androgenic alopecia is a genetically determined loss of hair which occurs under the influence of androgen hormones, at their normal values. Androgens act within the follicles that are located in the temporal regions and on the crown of the head. Initially, there is a shrinking of the hair follicle, which becomes thinner, leading to its complete loss and atrophy of the follicle. In women, hair thinning is more diffuse and limited to the central part of the scalp, with the preserved front hair line. Androgenic alopecia in women has a characteristic thinning of the central part, which is described as a Christmas tree symbol. Therapy consists of minoxidil lotions, finasteride tablets, and, more recently, plasma therapy — PRP treatments
of the scalp.