[Photoaging of face].

The environment, especially solar irradiation, plays a major role in skin aging. In humans, cutaneous areas frequently exposed to solar radiations are subject to premature skin ageing (heliodermatitis) which has specific clinical and histological features distinct from those observed in photoprotected skin. Most of the cellular and molecular mechanisms implicated in chronologic aging are observed in both ultraviolet exposed and photoprotected skin and can be stimulated in vitro and in vivo by repeated ultraviolet exposures. This article reviews the epidemiological, clinical and histological characteristics of photoaging and summarizes the recent findings acquired in this field.