Identical Alopecia Areata in Identical Twins

In the past many dermatologic and nondermatologic diseases have been reported in twins. To enumerate only a few, they are lichen planus,1von Recklinghausen's disease (neurofibromatosis),2rosacea,3summer prurigo,4ichthyosis hystrix,5peptic ulcers,6calcified mesenteric glands,7pilonidal cysts,8ephelides,9lentigines,9and dermatitis herpetiformis.9There have also been reported several cases of allergy of similar type and onset.10 The following case of alopecia areata beginning at the same time on identical areas of the scalp in monozygotic twins aroused our interest. REPORT OF A CASE Robert L. and Raymond L., 11 years of age, presented themselves to the Dermatology Clinic, City of Detroit Receiving Hospital, on Oct. 31, 1947, with the complaint that each had a bald spot on his head. Their mother stated that these spots had been first seen by her on the same day in