Sudden onset hair loss and colour change

A 56 year old man presented with a history of rapid onset hair thinning over one month. He also noted a reduced need to shave his facial hair. In addition, he felt that the colour of his hair had changed from dark brown with “an occasional grey” to white. Specifically, he described attending a Christmas party with “normal” hair yet by Christmas Day his hair and beard were white.

There was no loss of body hair elsewhere. The hair loss was noted on brushing and in the shower basin. He denied scalp itch, scale, or rash elsewhere. He had no history of serious illnesses or stresses over the past year. His medical history included hypertension for which he took longstanding atenolol and ramipril. Both his parents had good heads of hair in old age and there was no family history of autoimmune conditions. Examination found white hair with a remaining band of pigmented hair at the occiput (figure⇓). He had diffuse thinning of the hair and his beard was sparse, but there was no patchy hair loss, scale, erythema, or scarring. Blood samples were obtained and punch biopsies of the scalp showed an increased proportion of follicles in catagen or telogen phase, accompanied by a peribulbar lymphocytic infiltrate with no evidence of scarring.