A 36 year old male patient presents with patchy loss of hair on scalp, eyebrows and beard. He also gives a history of rapid greying of hair in a few areas. The likely diagnosis is:

The typical initial lesion of alopecia areata is a circumscribed bald smooth patchy hair loss. The scalp is the most common site but it can involve any hair bearing site such as beard, eye brows and eye lashes. Rapid greying (growing grey overnight), Exclamation point hairs (because of dystrophy) are pathognomonic of alopecia areata. Ref: Textbook of Dermatology, Venereology and Leprology By Devinder Mohan Thappa, 2nd Edition, Chapter 21, Page 240 ; Dermatology (A coloured Hand Textbook) By R. J. G. Rycroft, S. J. Robeson, Sarah H. Wakeli, 2nd Edition, Pa 1, Page 98