ABSTRACT
Psoriasis is a lifelong, chronic, and immune-mediated skin disease characterized by erythematous scaly plaques, affecting ~1 to 3 percent of the worldwide population. Several systemic drugs are available for the treatment of moderate to severe plaque psoriasis, including photochemotherapy, retinoids, cyclosporine, methotrexate, and fumarates. Although these options have been shown to maintain efcacy, they produce signicant subjective side effects. The realization that psoriasis is an immune system dysfunction rather than a primary skin disorder has led to the development of a new generation of therapies (named “biologicals”) for psoriasis that target the immune system. These drugs are directed against key cytokines and immune cells-notably tumor necrosis factor-alpha (TNFα), interleukin (IL)-12, IL-23, and T cells-that have been identied as critical factors contributing to the immunopathogenesis of the disease. Biologics are a heterogeneous group of monoclonal antibodies, fusion proteins, and recombinant cytokines, designed to modify and regulate pivotal and specic mechanisms involved in the immunopathogenesis of psoriasis.
