Photoaging - Pathogenesis, prevention, and treatment

Premature skin aging, or photoaging, results largely from repeated exposure to ultraviolet (U-V) radiation from the sun. Photoaging is characterized c linically by wrinkles, mottled pigmentation, rough skin, and loss of skin t one; the major histologic alterations lie in dermal connective tissue. In r ecent years, a great deal of research has been done to explain the mechanis m by which UV induces dermal damage. This research has enabled the identifi cation of rational targets for photoaging prevention strategies. Moreover, studies that have elucidated photoaging pathophysiology have produced signi ficant evidence that topical tretinoin (all-trans retinoic acid), the only agent approved so far for the treatment of photoaging, also works to preven t it. This article summarizes evidence mainly from studies of human volunte ers that provide the basis for the current model of photoaging and the effe cts of tretinoin.