What Is Trans epidermal Water Loss?
To understand TEWL, let's revisit the layers of our skin. Our skin is made up of three primary layers, the outermost being the epidermis (aka what you look at in the mirror). The dermis is the middle layer, and the hypodermis is the innermost layer. TEWL occurs when water passes from the dermis through the epidermis and evaporates through the skin barrier.