ABSTRACT

The skin is an organ with twofold functionality. It prevents the loss of internal fluids and provides a protective barrier against exogenous agents that may damage or alter the biological functions of an organism. Nevertheless, skin is permeable to water molecules through a passive diffusion process called transepidermal water loss (TEWL), which is not to be confused with sensible perspiration as it excludes the excretions of sweat glands. However, in the literature, the same terminology often refers to the total amount of water loss through the skin. TEWL mainly depends on the external environment relative humidity and temperature, and on the thickness and integrity of the stratum corneum, the uppermost layer of epidermis [1].