Alopecia areata: a review of diagnosis, pathogenesis and the therapeutic landscape

Alopecia areata (AA) is a T cell-mediated autoimmune disease that has an estimated lifetime prevalence of 2.1%. Although clinically heterogenous, the typical presentation is of discrete, well-demarcated patches of non-scarring hair loss. In severe AA, complete loss of scalp hair (alopecia totalis, AT) or all hair (alopecia universalis, AU) may occur. There is considerable variation in how AA is treated by dermatologists. Recent insights into the aetiopathogenesis of AA have led to the emergence of several novel treatment strategies, including Janus kinase inhibitors and biologics. This review provides a contemporary evidence-based summary of AA, including clinical features, severity assessment, disease pathogenesis and current and emerging treatment strategies