Wrinkle

[4] In humans, it can also be prevented to some degree by avoiding excessive solar exposure and through diet (in particular through consumption of carotenoids, tocopherols and flavonoids, vitamins (A, C, D and E), essential omega-3-fatty acids, certain proteins and lactobacilli).

[9] They appear in predictable locations due to the underlying superficial musculoaponeurotic system (SMAS), and are usually distinct from wrinkles of facial expression.

[13] These results were called into question by a 2014 study that failed to reproduce any improvement of handling wet objects with wrinkled fingertips.

Usually the tips of the fingers and toes are the first to wrinkle because of a thicker layer of keratin and an absence of hairs which secrete the protective oil called sebum.

This suggested that the nervous system plays an essential role in wrinkling, so the phenomenon could not be entirely explained simply by water absorption.

[17][18] Water probably initiates the wrinkling process by altering the balance of electrolytes in the skin as it diffuses into the hands and soles via their many sweat ducts.

Increased neuronal firing causes blood vessels to constrict, decreasing the amount of fluid underneath the skin.

[21] Current evidence suggests that tretinoin decreases cohesiveness of follicular epithelial cells, although the exact mode of action is unknown.

Topical glycosaminoglycans supplements can help to provide temporary restoration of enzyme balance to slow or prevent matrix breakdown and consequent onset of wrinkle formation.

GAGs serve as a natural moisturizer and lubricant between epidermal cells to inhibit the production of matrix metalloproteinases (MMPs).

Besides its cosmetic application, Botox is used in the treatment of other conditions including migraine headache and cervical dystonia (spasmodic torticollis) (a neuromuscular disorder involving the head and neck).