Alopecia Areata: Clinical Perspective and an Insight into Pathogenesis

The document provided a comprehensive review of alopecia areata (AA), an autoimmune disorder characterized by localized hair loss. It affected 0.05-0.1% of the population, with a lifetime risk of 1.7%, and involved a T-lymphocyte-mediated attack on hair follicles, influenced by genetic and environmental factors. Histopathological features included peribulbar lymphocytic infiltrate and changes in hair follicle structure. Prognosis varied, with 65% of patients experiencing hair regrowth within 6 months to 2 years. The review highlighted the role of HLA antigens, cytokines, and genetic predisposition in AA, and discussed its association with other autoimmune disorders, potential viral origins, and psychological triggers. Experimental models like C3H/HeJ mice were used to study AA and test treatments, emphasizing the disease's complex pathogenesis and multifactorial triggers.