Chronological aging of the skin and photoaging

Abstract:

The process of skin aging involves two phenomena: chronological aging – senile degeneration, universal and inevitable changes as a reflection of elapsed time and photoaging – solar degeneration, a change attributed to chronic exposure to the sun, which is neither universal nor inevitable. People who avoid the sun can reach old age with smooth and undamaged skin, however, the skin will still be thinned and inelastic with pronounced facial wrinkles. On the contrary, people who were permanently exposed to the sun will by age 50 have a multitude of wrinkles, with yellowing, dry and rough skin with frequent precancerous lesions and malignant neoplasms. Recent studies confirm that chronologic aging and photoaging of the skin share fundamental molecular mechanisms of development. Previously it was thought that changes due to solar degeneration are irreversible, however, today it is known that the discontinuation to sun exposure and the application of stronger UV filters can lead to reparations of actinically damaged skin. Even in more advanced stages of solar degeneration, with the use of local keratolytics, such as retinoic acid and alpha-hydroxy acids, and various abrasive methods (dermabrasion, chemical peels, laser resurfacing) it is possible to stimulate the formation of new collagen and elastic fibers. 

Key words:
chronologic skin aging; photoaging