Alopecia areata.

Abstract

Alopecia areata is a common cause of non-scaring autoimmune hair loss, associated with substantial psychosocial burden. Alopecia areata is an autoimmune disease in which loss of immune privilege in hair follicles leads to local hair follicle-associated inflammation. A chronic disease with uncertain course that is estimated to affect 2% of people over their lifetime, alopecia areata can present with a range of clinical features, from a single small round patch of hair loss to full scalp and body hair loss, and is associated with atopic, autoimmune and psychological comorbidities. Alopecia areata also has a major negative impact on quality of life, with a greater mental burden than physical burden. Since the 2010s, advances in understanding of disease pathogenesis have led to the identification of inflammatory pathways that can be successfully inhibited to produce substantial clinical responses. The therapeutic landscape has been transformed, with FDA approval of the first treatment for adults with severe alopecia areata in 2022 and for adolescents with severe alopecia areata in 2023, with multiple investigational treatments currently in phase II and phase III clinical trials.