Biologics for chronic inflammatory skin diseases: an update for the clinician.

The introduction and continuous development in biological drugs has greatly improved the therapeutic quality for patients with chronic inflammatory skin conditions. Current approaches to the biologic treatment of psoriasis, atopic dermatitis, chronic spontaneous urticaria, and hidradenitis suppurativa include licensed use of traditional antitumor necrosis factor agents, selective interleukin antagonists (IL-4, IL-12/23, IL-17), and the IgE inhibitor omalizumab, and as the knowledge on the pathogenesis of these diseases expands, off-label uses of the currently available biologics are becoming increasingly attractive, and the number of investigational drugs is growing progressively plentiful. In recent years, small molecule inhibitors, many of which are used in cancer therapy, have emerged as valuable future prospects in the treatment of inflammatory diseases. Inhibitors of PGD2, JAK, Syk, and C5a all have, to some extent, theorized efficacy in the treatment of chronic skin conditions, and multiple clinical trials are ongoing. The extensive research of the novel targets' roles in the pathogenesis of dermatological conditions should, in the future, further improve the therapeutic options for both the patients and physicians involved.