Photoaged skin: the role of neutrophils, preventive measures, and potential pharmacological targets.

Photoaged skin is characterized by epidermal changes and damaged elastic fiber and collagen fiber networks. Sunburned skin, including minimal asymptomatic ultraviolet (UV)radiation-induced erythema, is characterized by infiltrating neutrophils. Neutrophils are potent cells capable of degrading elastic fibers and collagen fibers and are probably important players in the pathophysiology of photoaging. Therefore,prevention of sunburn and/or prevention of neutrophil influx after exposure to artificial sources of UV radiation appear to be key factors in the prevention of photoaging. The wearing of protective clothing and the use of sunscreens are important preventive measures. Drugs that interfere with the cascade of events that eventually lead to neutrophil influx are potential antiphotoaging agents. In contrast, current and/or future therapies that are accompanied by neutrophil influx, particularly when these therapies are administered or performed repetitively, require a critical review. Here, we discuss clinical and histopathological features of photoaging,the pathophysiology of photoaging, potential pharmacologic targets with respect to infiltrating neutrophils, and some key points in prevention of photoaging and therapy for photoaged skin.