Why do wrinkles develop in the skin?
Skin wrinkles typically appear as a result of aging processes.
Developement of skin wrinkles is a kind of fibrosis of the skin.
Misrepair aging theory suggests that wrinkles develop from incorrect repair of injured elastic fibres and collagen fibres. Repeated extension and compression of the skin causes repeated injuries of extracellular fibres in derma. During the repairing process, some of the broken elastic fibres and collagen fibres are not regenerated and restored, but replaced by altered fibres.
When an elastic fibre is broken in an extended state, it may be replaced by a long collagen fibre. Accumulation of long collagen fibres makes part of the skin looser and stiffer and as a consequence, a big fold of skin appears.
Similarly when a long collagen fibre is broken in a compressed state, it may be replaced by a short collagen fibre. The shorter collagen fibres will restrict the extension of longer fibres and make the long fibres in a folding state permanently. A small fold, namely a permanent wrinkle then appears.
Age wrinkling in the skin is promoted by habitual facial expression, sun damage, smoking and poor hydration. Habitual sleeping posture, loss of body mass also result in wrinkles. Temporary wrinkling results from prolonged immersion in water.