Alopecia Areata: A Comprehensive Review of Pathogenesis, Diagnosis, and Emerging Therapeutics

Alopecia areata (AA) is a systemic, immune-mediated condition characterized by unpredictable hair loss and significant psychosocial impact. It involves complex interactions between genetic factors, immune dysregulation, and environmental triggers. Key to its pathogenesis is the role of cytotoxic CD8⁺NKG2D⁺ T cells and a Th1-skewed cytokine environment. Genetic studies have identified susceptibility loci, including HLA class II genes, while environmental factors like smoking and stress influence disease severity. Advances in Trichoscopy aid in diagnosis, and treatment has evolved from corticosteroids to Janus kinase inhibitors, though challenges with safety and cost persist. The review highlights the importance of personalized and multidisciplinary approaches to improve outcomes for AA patients.