The skin contains a large number of enzymes, and also a large number of antigens (some types of collagen, nuclear antigens, antigens of endothelial cells, fibroblasts and structure, etc.).
       In common diseases and skin diseases in relation to them can produce antibodies or autoantibodies. Their detection is used for diagnosis and prognosis of the disease. For dermatology elements such as copper, zinc and iron that make up enzymes, vitamins, and play the role of activators of biological processes are very important.