Alopecia areata is a chronic, T cell-mediated disorder that targets anagen hair follicles and causes hair losing and it may be localized or generalized. The condition most commonly presents with discrete, smooth patches of alopecia on the scalp but may also occur in other hair-bearing areas, such as the eyebrows, eyelashes, beard, and extremities. In severe alopecia, patients may experience loss of all scalp hair (alopecia totalis) or all hair (alopecia universalis). It is strongly releated with autoimmune thyroid disease and other endocrine autoimmune diseases.
