Skin barrier
The skin barrier protects us from the adverse effects of the external environment, regulates the entry and exit from the skin, and helps maintain the water content of the skin necessary for its proper functioning. It also prevents the penetration of undesirable substances into the skin (microbes, allergens, toxic chemical products).Skin barrier disorders are common, manifest as skin damage, and may be due to congenital (eg, eczema, psoriasis) or acquired (eg, external pollutants, skin injuries). The barrier disorder is primarily due to the loss or absence of natural skin lipids and dehydration of the skin.