Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia Areata (AA) is a chronic, immune-mediated skin disease causing hair loss, affecting 0.5–2% of the global population. Its cause is multifactorial, involving genetic and environmental factors. Genetic research has identified several genes, including PTPN22, CTLA4, IL2, HLA-DQB1, HLA-DRB1, TLR7, IL-2/IL-21, IL-23R, FASLG, PTPN22, NOTCH4, IL36A, IL-6, IL-18, HLA-DRA, HLA-DRB, HLA-DQA1, CLCNKA, and CPT2, associated with AA. Genome-wide association studies have identified 139 genotypes and 175 predicted single-nucleotide polymorphisms significantly associated with AA. AA is also associated with other immune-related diseases like hyperthyroidism, rheumatoid arthritis, systemic lupus erythematosus, and atopic dermatitis. Current treatments include intralesional corticosteroids, topical corticosteroids, systemic corticosteroids, minoxidil, methotrexate, and cyclosporine, with emerging treatments like JAK inhibitors showing positive results in clinical trials. However, the high rate of relapse after discontinuation and the high cost of treatment require further investigation.