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|How to cite this article:
Singh G. Androgenic alopecia. Indian J Dermatol Venereol Leprol 2002;68:40
Androgenic alopecia is a genetically determined physiological event, the exact mode of inheritance of which is unknown. The shortening of the anagen phase of the hair cycle leads to the consequent increase in the proportion of telogen hairs. Autosomal dominant inheritance with increased penetrance in males had been suggested, but there are reports of multifactorial inheritance as well. The role of androgen along with their interaction with genetic factors is demonstrated in men, but in women baldness is often associated with elevated levels of circulating androgens (e.g. in polycystic ovary disease). In both the sexes, the factor determining androgenic alopecia is the manner in which the follicles of the frontal and vertex region of the scalp react to the circulating androgens. Till date the correlation between testosterone levels and the extent of baldness has not been established.
A man coming to me for the treatment of androgenic alopecia is first prescribed minoxidil 2% solution, I ml to be applied topically twice daily for 6 to 12 months. The patient is advised to use ketoconazole shampoo without using any hair oil. In about one third of men, there is significant conversion of miniaturized hairs to terminal hairs. The response is better in younger males having a smaller area of hair loss that too in the early stage of baldness. The only side effect is occasional local irritation but the benefits last only as long as the drug is applied. The hair loss recurs 3-6 months after discontinuing application, reaching the level it would have reached had minoxidil not been used. The males who do not respond appreciably to topical minoxidil are prescribed tablet finasteride 1 mg daily. This leads to significant hair growth in another one third of the patients. Safety and tolerability levels are excellent with no significant impairment of fertility. The remaining one third of patients who do not respond to the above described treatments are evaluated for hair transplantation. The patients taken up for the surgery are only upto III and type III vertex baldness (Hamilton′s classification). It requires four separate sessions to get enough hair in the area for good coverage. Critical areas such as the hairline require as many as six sessions to set a thick natural appearing hairline.
The treatment for androgenic alopecia in women is started only after ruling out other causes of hair loss like child birth, iron deficiency anaemia, crash diet, severe emotional stress and hypothyroidism. Minoxidil 2% solution applied topically is the first drug of choice. In case it fails, tablet spironolactone 1 00mg is given daily for 3 out of every 4 weeks along with oral contraceptives. Hair transplantation is attempted in those ladies who need treatment for frontal recession and the results are good.