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Related to male-pattern baldness: finasteride
androgenetic alopeciaHereditary thinning of hair induced by androgens in genetically susceptible men and women, which occurs in ± 50% of the general population between age 12 and 40.
Dihydrotestosterone binds to androgen receptors of susceptible scalp hair follicles, activating genes that gradually transform large terminal hair follicles to miniature follicles, producing finer hair in shorter hair cycles. Dihydrotestosterone is formed by peripheral conversion of testosterone by one of two isoforms of 5α-reductase, which, with other enzymes, regulate specific steroid transformations in skin. Those with AA have increased 5α-reductase, increased androgen receptors and decreased cytochrome P-450 aromatase, which converts testosterone to estradiol in hair follicles in the frontal scalp.
The typical pattern of baldness in males in which the baldness begins in the frontal area and proceeds until only a horseshoe area of hair remains in the back and at the temples. It is due to testosterone, but genetic predisposition is also a factor. Baldness does not usually occur in males having no familial tendency to become bald. Minoxidil or finasteride has helped stimulate growth of hair in some individuals. Synonym: male-pattern alopecia See: illustrationillustration
See also: baldness