Since our recognition several years ago of the presence of Demodex folliculorum in the majority of our patients with acne rosacea and an allied condition which we have designated as pityriasis folliculorum (Demodex), our therapeutic results have been far superior to those obtained by the usual treatment of acne rosacea. In view of the fact that Kaufmann-Wolf1called attention to the frequent occurrence of Demodex folliculorum in the pustules of acne rosacea as long ago as 1925, it seems rather surprising that so little recognition has been accorded this valuable contribution. In fact, within the past few months Stokes and Beerman2have published an exhaustive study of the etiology of acne rosacea especially from an emotional and nervous point of view without making any mention whatever of Demodex as a possible factor. One might argue that, because Demodex is a more or less "normal" inhabitant of the human