This review article is devoted to the study of the structure and functioning of the histo-hematic barrier of the skin and presents information on dermatological and histological studies. Experimental data from 36 scientific works, in which authors consider the features of structure and functioning of the skin within normal and under the influence of ticks of the Demodex spp. genus, were analyzed. The histo-hematic barrier regulates the metabolic processes between the epithelial and connective-tissue structures of the skin. From the perspective of barrier morphology, the interest for study is the epithelium of the philosebaceous complex, surrounding its loose areolar connective tissue, including hemocapillaries. Importantly, information on the role and changes of these elements in maintaining homeostasis between the skin and the body’s internal environment is fragmentary and not fully described. Ticks of the Demodex spp. genus are opportunistic organisms and may have a traumatic effect on the components of the skin barrier under certain conditions. The direct damaging action of ticks and their impact on the receptor apparatus of cells causes the release of pro-inflammatory cytokines and chemokines into the blood, activating the migration of immune cells to the focus of inflammation. The presence of inflammatory process further enhances the destruction of barrier elements and the introduction of ticks into the skin structure.