Hormone replacement therapy and the skin.

Estrogens have a profound influence on skin. The hypoestrogenism occurring after the menopause leads to measured deterioration in the skin. Estrogen receptors have been identified in the skin and the concentration of these receptors varies in the different parts of the body. Estrogen improves skin in more than one way, the collagen content and quality is improved, skin thickness is increased, while vascularisation is enhanced. The extracellular matrix responsible for the tone and appearance of the skin is also improved. It is not just the skin that shows an improvement with estrogen therapy but also skin appendages, such as hair. Estrogens have been shown to increase the hair follicle life cycle. Skin aging is not totally estrogen dependent because the ravages of age and the external environment play very important roles. The effects of estrogen on skin need further elucidation and with the emergence of newer techniques it is now possible to study more clearly the changes occurring at the cellular level. Estrogen replacement reverses the deleterious effect of estrogen deprivation on the skin, which is thus yet another organ that benefits from hormone replacement therapy.