Topical Retinoids: Therapeutic Mechanisms in the Treatment of Photodamaged Skin.

Retinoids are a group of substances comprising vitamin A and its natural and synthetic derivatives. Retinoids were first used in dermatology in 1943 by Straumfjord for acne vulgaris. Since that time, retinoids have been utilized in the management and treatment of various skin conditions, including photoaging. Photodamage of the skin occurs as a consequence of cumulative exposure to solar ultraviolet radiation (UVR) and is characterized by deep wrinkles, easy bruising, inelasticity, mottled pigmentation, roughness, and telangiectasias. The mechanism of UVR-induced photodamage is multifactorial. Retinoids have demonstrated efficacy in the treatment of photoaged skin. Indeed, understanding the pathophysiology of photoaging and the molecular mechanism of retinoids can not only provide insight into the effects retinoids can exert in treating photoaging but also provide the rationale for their use in the treatment of other dermatologic diseases.