Interleukin-17 (IL-17) has been implicated in the pathogenesis of a large number of inflammatory and autoimmune conditions, including skin disorders such as psoriasis. Recently, much data have accumulated on the possible role of IL-17 in the pathogenesis of alopecia areata (AA). In this review, the available information on the connection between AA and IL-17 is described. While IL-17 levels are consistently reported to be elevated in the serum and lesional skin of AA patients, there is no clear connection between IL-17 levels and disease severity or duration. Some evidence has suggested an association between IL-17 and an early-onset disease, although this awaits further confirmation. While there is enough information to support clinical trials with IL-17-targeted treatments, it is possible that they will be effective only in a subset of AA patients. Further studies are warranted to better delineate the exact role of IL-17 in AA pathogenesis.
Keywords: Alopecia areata; Autoimmunity; Hair; IL-17; Secukinumab.