Male pattern androgenetic alopecia

Androgenetic alopecia is characterised by progressive, patterned hair loss from the scalp. Recently the pathogenesis and genetic basis of the hair loss have been better understood, as has the distress experienced by men who have lost their hair. There have also been breakthroughs in the treatment of androgenetic alopecia. The transition of some terminal hairs into vellus hairs is a universal physiological secondary sexual characteristic.1 Androgenetic alopecia becomes a medical problem only when the hair loss is subjectively seen as excessive, premature, and distressing. The prerequisites for premature androgenetic alopecia are a genetic predisposition and sufficient circulating androgens.2 Eunuchs do not go bald.3 Every white man possesses the autosomal inherited predisposition,4 and 96% lose hair to some degree,5 but because of the variabity of gene expression far fewer have appreciable premature hair loss. #### Summary points This article is based largely on my experience in the management of hair loss. Original articles and expert reviews from major journals cited in Medline between 1966 and 1997 have been supplemented by information and articles cited in recently published textbooks. The following keywords were used for the Medline search: androgenetic alopecia, androgenic alopecia, common baldness and balding, premature baldness and balding, hereditary balding and baldness, male pattern and female pattern alopecia, …