[Dermo-cosmetics and prevention of skin aging].

Skin aging is the result of the addition of intrinsic aging (chronological aging) and extrinsic aging induced by environmental factors among whose ultraviolet radiation plays a predominant role (actinic aging). The physiopathological mechanisms of skin aging are well better known. UV radiations act either directly on DNA either through the formation of free radicals. The skin aging is characterized by the decline of numerous skin functions. Its clinical presentation is accentuated in UV exposed-skin. To struggle against skin aging is first of all to prevent it by means of an efficient photoprotection, an adequate general life style and preventive treatments as alpha-hydroxyacids, retinoids and antioxidants.