[Penetration and side effects of local estrogen application in alopecia androgenetica]

In 30 male patients aged 17-37 with definite androgenetic ("male pattern") alopecia (AA, telogen hair rate greater than 20%) the total urinary estrogen level was estimated before and after topical treatment: In 18 patients estrogen in a alcoholic vehicle (0.05% dienestroldiacetate) was daily applied on the scalp skin; whereas 12 patients were treated with a corresponding preparation without estrogen and served as controls. Before treatment the average estrogen level of all patients with AA was 23.3 mum/24 hrs (individual data ranged from 9.4-45.6 mum/24 hrs) and was thus slightly elevated but still within the normal range. 3 and 6 months after treatment no significant differences of the urinary estrogen level were found between the controlled patients of the two groups and, similarly, no clinical side-effects of the estrogen application (gynecomasty etc.) were recorded. It seems, on the basis of this study, that a long-term topical treatment with estrogen does not involve considerable risks regarding side-effects on male adults, in contrast to children and youngsters. On the assumption that estrogen may be effective in AA, a local mechanism of action on the hair follicle is considered.