Nearly everyone has experienced the effect of acute overexposure to sunlight - a sunburn. Even if sunburn does not occur, the ultraviolet (UV) rays in sunlight cause photodamage of DNA in epidermal cells and extracellular matrix materials, such as collagen and elastic fibers in the dermis.
Over the long term, chronic UV exposure accelerates the aging of skin (photoaging) and is an important factor in development of nearly all skin cancers. Protecting your skin from UV rays is a wise approach.
A recent treatment for wrinkles and liver spots in photodamaged skin is the drug tretinoin (Retin-A). It is a derivative of vitamin A that has been used to treat acne since the 1960s.
Among the reported benefits of using tretinoin are increased thickness of the epidermis, smoother stratum corneum, diminished number and size of melanocytes, increased production of collagen and elastin, dilation of blood vessels in the dermis, and regression of precancerous lesions.
Dermatologists caution that tretinoin does not improve advanced changes associated with aging and it may increase the risk of cancers induced by UV light exposure.
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