Efficacy and Safety of Baricitinib in Patients With Alopecia Areata: Evidence to Date

Alopecia areata (AA) is a chronic autoimmune disorder causing non-scarring hair loss, affecting approximately 2% of the global population, often starting before age 30. The disease's relapsing nature negatively impacts patients' quality of life and increases susceptibility to psychiatric comorbidities. The exact cause of AA is unclear, but it's believed to involve a breakdown of the hair follicle's immune privilege, leading to increased self-antigen and major histocompatibility complex expression in the follicular epithelium. Current treatments are limited in effectiveness and can have adverse effects. However, recent understanding of AA's connection to the JAK–STAT pathway has led to the development of JAK inhibitors. Baricitinib, an orally administered JAK1 and JAK2 inhibitor, is a promising alternative treatment for AA and is already approved for use.