Interleukin-17 (IL-17) is an essential proinflammatory cytokine, which is mainly secreted by the CD4 + helper T cells (Th17 cells) and subsets of innate lymphoid cells. IL-17A is associated with the pathogenesis of inflammatory diseases, including psoriasis, atopic dermatitis, hidradenitis suppurativa, alopecia areata, pityriasis rubra pilaris, pemphigus, and systemic sclerosis. Interleukin-23 (IL-23) plays a pivotal role in stimulating the production of IL-17 by activating the Th17 cells. The IL-23/IL-17 axis is an important pathway for targeted therapy for inflammatory diseases. Emerging evidence from clinical trials has shown that monoclonal antibodies against IL-23, IL-17, and tumor necrosis factor are effective in the treatment of patients with psoriasis, atopic dermatitis, hidradenitis suppurativa, pityriasis rubra pilaris, pemphigus, and systemic sclerosis. Here, we summarize the latest knowledge about the biology, signaling, and pathophysiological functions of the IL-23/IL-17 axis in inflammatory skin diseases. The currently available biologics targeting the axis is also discussed.

Alopecia areata (AA) is an autoimmune disorder characterized by nonscarring hair loss. 1 Numerous treatment options are available for AA. 2,3 However, it is often challenging and unsatisfactory for refractory AA treatment. Recently, Janus kinase inhibitors (JAKis) have shown promising results in treating AA. 4 For example, baricitinib has shown good clinical efficacy in two phase 3 trials involving patients with severe AA. 5 Here we present a case series of 11 patients with refractory AA treated with baricitinib.

No abstract

No abstract