[The evaluation of nitrogen metabolism and the reactivity of the organism in patients with dry skin].

It is known that in norm horny layer of the epidermis is able to retain water due to the presence of hygroscopic substances inside corneocytes in the form of so-called natural moisturizing factors (NMF), consisting of free amino acids and their derivatives, which are formed during the decay of filaggrin as well as lactic acid, urea, sugars, and intercellular lipid membranes, creating a barrier that prevents transepidermal water loss. At the same time, the results of recent studies have shown that urea--a kind of natural antioxidant that protects tissues from the accumulation of aggressive forms of oxygen. It is able to stabilize the lysosomal membranes, thus preventing autolysis of cells. The ability of urea at low concentrations to modify the reactivity of functional groups of proteins leads to conformational changes of immunoglobulin, which has an inhibitory effect on the immune system, including the diminishing impact on the development of reaginic type reactions. Urea has anti-inflammatory, hyposensitizing, and antioxidant effect. Based on the above the aim of this study was to determine the content of urea and some indicators of cellular and humoral immunity in case of chronic dermatoses, accompanied by dryness of the skin. Indicators of nitrogen metabolism of blood serum (urea. ammonia), some parameters of cellular and humoral immunity were studied in 27 patients, who according to nosological units were distributed as follows: atopic dermatitis (12), psoriasis (7), xerosis (8). In the study of the concentration of urea in the blood, and some indicators of cellular immunity, as well as the content of immunoglobulin E in the blood of our patients a decrease in the number of T--lymphocytes, mainly due to T--suppressor and raising the level of immunoglobulin E have been revealed. Specific patterns of changes in these parameters, depending on nosological unit, severity of disease and degree of dryness of the skin have also been observed.