63-Year-Old Female with Diffuse Thinning of the Hair

Abstract

Androgenetic alopecia (AGA) is a form of non-scarring alopecia caused by an excessive response to androgens. It is the most common type of progressive hair loss in both men and women, affecting up to 80% of men and 50% of women over the course of their life. Presentations of AGA differ between sexes with men initially experiencing recession of the frontal hairline and increased loss in the temporal regions. In women, the hair loss consists of diffuse thinning at the crown with a presenting concern of a widening center hair part. AGA is a hormonally driven hair loss where androgens may have a paradoxical effect on some areas of the scalp and cause dark terminal hair follicles to regress to fine and colorless vellus hairs. Not only do androgens cause hair follicle regression into vellus hairs, but they also shorten the anagen (growth) phase. This results in a smaller anagen-to-telogen ratio and ultimately leads to follicular shrinkage and a decrease in overall hair coverage on the scalp. Diagnosis of AGA is based on a thorough history and physical exam. Biopsy is rarely required for diagnosis but if performed, shows pronounced miniaturization of hair follicles and complete zones of replacement of terminal hair by vellus hair. Treatment of AGA focuses on increasing scalp coverage as well as impeding the progression of hair thinning. This can be achieved through the use of topical minoxidil for both men and women. The use of oral finasteride may be utilized in men and recent studies suggest its use in non-reproductive females. Females may also use oral spironolactone as an alternative therapy to finasteride. Recent studies are investigating the use of platelet-rich plasma, low-level laser therapy, and janus-kinase inhibitors for the treatment of AGA with promising preliminary results.