MICROVASCULAR PATTERN AND BLOOD STASIS IN SKIN DISEASE

SUMMARY.— Some of the factors contributing to severe intravascular stasis in the blood vessels supplying the epidermis are discussed. Changes in blood viscosity result from a variety of factors which act maximally at the peak and in the venous arm of the papillary vessel. The influence of cold on blood viscosity in the papillary vessel is particularly emphasized.
The importance of aggregation of blood cells in the superficial vessels and of factors such as platelet aggregation, which may be irreversible and may influence disaggregation are discussed.
The presence of "preferential channels" in the capillary meshwork of the skin is illustrated and their significance as passages permitting redistribution of blood away from the epidermis is emphasized.
Studies of platelet stickiness in a group of patients suffering from sensitivity to cold and studies on blood flow in one patient with acrocyanosis are presented.