Alopecia areata: What's new in the diagnosis and treatment with JAK inhibitors?

Abstract

Alopecia areata (AA) affects individuals of all ages and is intractable in severe relapsing cases. Dermatologists and other healthcare providers should consider AA in the medical context and prioritize treatment. Several randomized controlled clinical studies on Janus kinase (JAK) inhibitors with different specificities for the treatment of AA are ongoing. These studies have encouraged us to appreciate the importance of a definitive diagnosis and accurate evaluation of AA before and during treatment. Following our previous review article in 2017, here we provide the second part of this two‐review series on the recent progress in the multidisciplinary approaches to AA from more than 1800 articles published between July 2016 and December 2022. This review focuses on the evaluation, diagnosis, and treatment of AA. We also provide the latest information on the safety and efficacy of JAK inhibitors for the treatment of AA and describe their mechanisms of action.

Up-and-Coming Drugs for the Treatment of Vitiligo

“…Since the JAK3 subtype is associated with the common γc receptor subunit of IL-2, 4, 7, 9, 15, and 21, ritlecitinib was recently approved for the treatment of severe alopecia areata in the USA and Japan, owing to its potent targeting of IL-15 55 . In alopecia areata, IL-15 signaling stimulates the survival of CD8+ memory T cells, promotes the increase and maintenance of T cells and NK cells, and induces CD8+ T cells to produce IFN-γ, which parallels the pathogenesis of vitiligo 56 . In vitiligo, IL-2 and IL-15 stimulation on Trm cells leads to the secretion of perforin, granzyme B, and IFN-γ, resulting in a cytotoxic effect on melanocytes 57 .…”