To the Editor.—
A paper entitled "Histopathology of Rosacea" by Marks and Harcourt-Webster in the December 1969 issue of the Archives (100:683-691) contains some references to the role of Demodex folliculorum in the etiology of rosacea which need clarification. According to the authors, "The finding of Demodex in only 19% of our biopsy material and its absence from areas of inflammation in sections in which it was found are much against a significant role for this organism in this disease."This statement is ample evidence that the authors have not grasped the important point which we have repeatedly emphasized in five communications1-5 between 1930 and 1967, to the effect that there are two types of rosacea, a seborrheic and a "dry" type. For the latter, we have coined the term rosacea-like demodicidosis, although we originally called it pityriasis folliculorum (Demodex).Classical rosacea, which may be of multiple etiology