Alopecia areata: current concepts.

Alopecia areata (AA) is a chronic autoimmune condition characterized by relapsing, non-scarring hair loss. Approximately 80% of patients experience limited patchy hair loss with potential for spontaneous recovery, while others progress to more extensive forms, such as alopecia totalis or alopecia universalis, both of which carry a profound psychosocial burden. Advances in research have identified immune privilege collapse of the hair follicle, Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) pathway activation and genetic predisposition as key mechanisms driving disease onset and progression. These insights have advanced therapeutic strategies, shifting from nonspecific treatment towards targeted interventions. Conventional treatment, including topical agents and light-based approaches, remain important options, particularly for mild or localized disease, while the advent of oral Janus kinase inhibitors, such as baricitinib and ritlecitinib, offers the first U.S. Food and Drug Administration (FDA)-approved systemic treatment for severe AA. In this review, we summarize current concepts in epidemiology, pathogenesis, diagnosis, comorbidities and treatment, highlighting emerging therapies and discussing future directions for improving patient outcomes.