The name alopecia mucinosa was applied by Pinkus1 to 6 cases of peculiar inflammatory plaques with alopecia which were characterized histologically by rootsheath mucinosis. A similar case had been published by Lehner and Szodoray2 under the diagnosis of inflammatory follicular edema. It seems possible that a case presented in 1932 by Gougerot, Blum, and Eliascheff,3 under the designation ``dermatose innominée'' also was one of alopecia mucinosa. Their patient had recurrent papular erythematosquamous plaques which grew centrifugally on his cheeks, and erythematous, scaly, alopecic macules on his neck and arms. Photomicrographs of sections of this case suggest rootsheath mucinosis, but the authors described only necrosis of sebaceous glands and follicles and did not stain for mucin. Since Pinkus' publication, additional cases of alopecia mucinosa have been recognized in the United States, various European countries, and South Africa. The following report concerns 1 of 3 cases diagnosed in Mendoza,