The epidermis is the outermost layer of skin, which, going from exterior to the interior, is made up the epidermis, dermis and hypodermis.
The epidermis is around 1 millimetre thick, though it varies significantly in different parts of the body, particularly the feet and palms of the hands.
Epidermal cells are born in the basal membrane, a thin yet highly active cellular layer that separates the epidermis from the dermis. Within three or four weeks, these cells develop while migrating towards the exterior, pushed by younger cells, then die in transforming into a layer of keratin, a hard protein which gives skin its strength. Little by little, these dead cells are eliminated (a process known as desquamination) and are replaced by new cells. Among these cells are the keratinocytes, which produce keratin, and melanocytes, which produce melanin, the protein responsible for the more or less intense coloration of our skin.
In direct contact with outside elements, the epidermis is an important protective barrier for our organism, despite its thinness. Sweat and sebum create a slightly acidic lubrifying film on the skin's surface, repelling bacteria and keeping the skin software and supple.
The epidermis becomes dry when exposed to outside aggression (climatic conditions, irritating cosmetic products), or in case of allergic tendencies. Its fragile balance is disturbed, opening the door to numerous conditions, including atopic dermatitis, which is increasingly frequent in young children today.
To effectively fight again the undesirable effects of drying skin, the organic Swiss cosmetics laboratory Alpaderm offers a line of hypoallergenic skincare creams whose natural active ingredients deeply moisturise children's and adult's skin. Cérat des Alpes cold cream, in particular, is recommended for helping restore the hydro-lipid film on dry and fragile skin.