Hair follicle regression and perifollicular inflammatory infiltrate in alopecia areata

Alopecia areata (AA) is a kind of inflammation-induced,self-limited and non-scarring hair loss.No satisfactory treatment is available for AA at present,and relapse is frequent.The pathogenesis of AA remains unclear.Pathologically,it is characterized by inflammatory infiltrate around anagen hair follicles and degeneration of hair follicles.Most current studies suggest that inflammatory cells attack anagen hair follicles,which together with cytokines and neuropeptides constitute a vacious cycle,leading to the apoptosis in hair follicle epithelial cells followed by sudden simultaneous regression of numerous hair follicles,and,finally,causing the initiation of AA. Key words: Alopecia areata;  Hair follicle;  Inflammation