Pilosebaceous Unit: Structure, Function, and Disorders

The pilosebaceous unit (PSU) consisted of a hair follicle and a sebaceous gland, influenced by androgens and other hormones. Androgens played a crucial role in PSU development, affecting hair follicle differentiation and disorders like hirsutism, pattern alopecia, and acne vulgaris. Hair growth followed a cyclical pattern, and sebaceous glands produced sebum through cell differentiation. The response of PSUs to androgens varied by location and individual sensitivity, influenced by enzymes like 5α-reductase. Nonandrogenic hormones such as estrogen and growth hormone also played roles in PSU function. Treatments for related disorders included minoxidil, finasteride, topical agents, and retinoids.