Measurements on the Skin Capillaries in Cases of Polycythemia Vera and the Role of These Capillaries in the Production of Erythrosis.

One of the outstanding features of polycythemia vera is the color of the skin. Clinical descriptions employ the terms brick red, congestive facies, cyanosis and erythrosis. Vaquez, who reported the first observed case of this disease, noted cyanosis as the prevailing tint. Osler thought that the color change was not that of cyanosis but congestion or redness. Since the microscopic investigation of the skin capillaries has shown definite and measurable variation of these vessels in this disease, it seemed to us that a quantitative analysis of the blood and vascular factors would add much to an adequate understanding of the color changes, and herewith report the results of such analysis. The color of the skin in cases of polycythemia vera is predominately red but subject to marked variations. The redness affects largely the facial and acral regions; the hands to the glove line, and the face and neck to the decollete margin. The feet are usually less red than the hands. The mucous membranes appear cyanotic when the skin is definitely red. Cyanosis has not been observed in the conjunctiva; this tissue has a bright red, or an injected or inflamed appearance. On the trunk and proximal portions of the extremities color changes are much less than on the more distal and facial areas. The skin over the trunk and back may have the mild flushed appearance of a scarlatiniform rash. Clinical descriptions of the color of the skin in our cases by various co-workers were "markedly red," "brick red," "reddish cyanosis," and