Transdermal immunotherapy: Past, present and future

The human skin plays an important role in thermal regulation, the maintenance of the correct water and electrolyte balance; it is also the main source of the vitamin D for the organism. Moreover, the skin forms an effective barrier against microorganisms, protecting the organism against xenobiotics and harmful external factors. It must also be mentioned that the skin is an essential organ involved in immunological mechanisms. This article summarizes current knowledge about skin-induced suppression induced via epicutaneous (EC) application of an antigen and is described in both Th1- and Tc1-mediated contact sensitivity (CS) in mice. The skin-induced suppression is also considered in the regulation of experimental models of autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), collagen-induced arthritis (CIA) and colitis ulcerosa. Furthermore, the efficacy of treatment of multiple sclerosis (MS) patients with EC immunization is discussed. Second part of this review introduces new subject of immunopotentiation induced via EC immunization with an antigen in the presence of various pathogen-associated molecular patterns (PAMPs). Finally, the review describes dermal immunization in the therapy of allergic diseases.