The Skin and Oxidative Stress

Abstract

Skin is a biological interface with the external environment and functions as the first line of defense against noxious stimuli. As such, it is often the first organ to come into contact with harmful stresses. Skin primarily provides protection from external insults to the body’s interior. From an evolutionary point of view, the oldest function of skin is resistance to and separation from the environment. Other basic functions include heat regulation, communication and involvement in hormone metabolism and in immunological surveillance. Skin is also challenged by intrinsic aggressive stimuli such as autoimmune reactions, e. g., autoaggressive inflammatory cells, and specific metabolic dysfunctions. The integument mainly functions as a immunological, microbial, and physicochemical barrier. The physicochemical barrier function resides principally in the stratum corneum. The epidermodermal interface is a second barrier due to a change from a lipophilic to a hydrophilic skin compartment. The protective mechanisms can break down under stresses caused by external and internal insults. There are many different forms of harmful environmental stress conditions, such as extremes brought about by oxygen depletion or excess, extremes of temperature, water stress, nutrient depletion or excess, and exposure to environmental pollutants. Environmentally related disorders of the skin are responsible for about one third of all cases of occupational diseases in the USA.