[Clinical signs of cutaneous aging].

Skin ageing depends on several, closely connected causes, including ageing obviously, but also on environmental factors, such as smoking and also, in women, on estrogen deficiency due to the menopause, but above all exposure to sunlight, particularly in fair-skinned individuals. The changes due to time-related ageing, thinner, withered skin are similar to those caused by the menopause, which also induces some signs of hyperandrogeny. Sun-related changes, which occur mainly on uncovered areas, vary so widely that some authorities prefer the terms "dermato-heliosis" or "helio-dermatitis" to that of solar ageing. Solar elastosis is the most typical change and is visible on the face as a yellowish skin criss-crossed by deep wrinkles. On the neck and extended surfaces of the limbs, the skin is atrophied and often dyschromic. Excessive exposure to the sun is also responsible for most skin cancers, which are known to occur mainly on exposed parts.