Photodamage, Part 1: Pathophysiology, Clinical Manifestations, and Photoprotection
Photodamage is defined as changes in the skin that occur after prolonged exposure to solar irradiation. Photoaging is one of the results seen with photodamage, which is an alteration in the skin caused by sun exposure resembling the effects of age. Skin cancers are at the other end of the spectrum of photodamage. UV radiation (UVR) is the common entity that contributes to both. The derangements in the epidermis and dermis mainly are attributable to collagen degradation and remodeling. These biologic processes translate to the clinical manifestations of photodamage, including wrinkles, decreased skin elasticity, hyperpigmentation, telangiectasias, actinic keratoses (AKs), and neoplasms. Sunscreens and antioxidants are photoprotective agents that aim to minimize the effects of UVR. The therapeutic modalities for the management of photodamage include topical agents, mechanical exfoliation, and laser therapies. Topical remedies such as retinoids, a-hydroxy acids, and antioxidants commonly are used today. There is a wide gamut of laser and light devices, such as ablative lasers, nonablative lasers, fractional lasers, and radiofrequency ablation. In this review article, we discuss the different aspects of photodamage with a focus on photoaging, the possible mechanisms, and the available modalities of prevention and management.