The skin provides protection from mechanical, thermal, chemical damage; has its own immune system; regulates the amount of water in the body; helps to produce vitamin D and a number of hormones. All these functions are provided by various mechanisms, the key of which is the integrity of the barrier, largely mediated by the structure of the stratum corneum of the epidermis. The skin consists of the layers of epidermis, dermis and subcutaneous fat and is permeated with sweat and fat glands and pores, vessels, nerve fibers and hair follicles. The upper layer of the skin is formed by dead cells (corneocytes) originated from differentiated and dead keratinocytes of the granular layer. In the process of cornification in keratinocytes, the synthesis of a number of proteins is activated, the cell membrane is compacted, intermediate keratin filaments are aggregated, lipids and proteins are released into the extracellular space as lamellar bodies (Odland’s body), organelles are ejected, which as a result leads to the flattening of cells interconnected by a layer of lipids as glue, providing an additional water-impermeable barrier. Normally, the lipid layer consists on 50% of ceramides, 30% of cholesterol, 20% of free fatty acids (including omega –3, –6 and –9), as well as of enzymes and proteins. In case of various diseases, the lipid balance of lamellar bodies is disturbed, which leads to an increased water loss, disruption of the cornification process, inflammation. Topical drugs containing analogues of natural lipids, such as Sensoderm, not only restore the homeostasis of the skin, but also reduce the side effects caused by therapeutic corticosteroids.