Alopecia Areata: A Review of Disease Pathogenesis

The document reviewed the pathogenesis of alopecia areata, a condition causing nonscarring hair loss with significant psychological effects. The prevailing theory is that alopecia areata is an autoimmune disorder caused by a loss of immune privilege in hair follicles, but the exact trigger is debated. Some researchers attribute it to stress within the hair follicle environment, while others suggest a dysregulation in the central immune system. Studies, including animal research and investigations into the AIRE gene, support the latter. Immune cells such as plasmacytoid dendritic cells, natural killer cells, and T cells, along with molecules like interferon‐γ, interleukin‐15, MICA, and NKG2D, are implicated in the autoimmune response. Despite years of study, alopecia areata remains incurable, with existing treatments mainly effective for mild cases and a high relapse rate. Understanding the disease's mechanisms is crucial for identifying new therapeutic targets.