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

Abstract

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.

The Alopecia Areata Severity and Morbidity Index (ASAMI) Study

“…When considering AA episode duration, the experts agreed that patients with rapidly progressive AA may be eligible for systemic treatment, regardless of disease duration. In patients with AA that is not rapidly progressive, the minimum episode duration a patient must experience to be eligible for systemic treatment is 6 months; additionally, participants agreed that systemic treatment should not be precluded by a maximum duration, even though evidence suggests its lower likelihood of success in long-standing disease …”

“…Insights into the etiopathogenesis of AA have led to the emergence of several novel, highly effective treatments, including Janus kinase (JAK) inhibitors . Baricitinib, a selective and reversible JAK1/JAK2 inhibitor is now approved by the US Food and Drug Administration, European Medicines Agency, and Medicines & Healthcare Products Regulatory Agency for the treatment of severe AA in adults.…”