Alopecia areata (AA) is a tissue-restricted autoimmune disease directed at the hair follicle resulting in non-cicatricial hair loss. It can progress to complete loss of scalp hair (alopecia totalis) or loss of all body hair (alopecia universalis). There are several theories for the aetiopathogenesis of alopecia areata including autoimmunity & genetic predisposition. PTPN22 C1858T gene polymorphism has been associated with several autoimmune disorders including alopecia areata.