Calcified subcutaneous arterioles with infarcts of the subcutis and skin ("calciphylaxis") in chronic renal failure

Patients with chronic renal failure (CRF) are at increased risk for patholo gical calcifications because of Increased serum calcium-phosphorus products . A minority, including those undergoing dialysis, develop a syndrome of de ep skin ulcerations in association with calcification of subcutaneous arter ioles, The body distribution of the skin lesions may be proximal (central), distal (peripheral), or both. Since 1968, this syndrome has been called "c alciphylaxis" in the belief that it is the human analogue of Selye's experi mental models of tissue calcification. Our review emphasizes that this synd rome comprises two separate processes not found in calciphylaxis: calcifica tion of subcutaneous arterioles and infarctions of subcutaneous adipose tis sue (panniculus adiposus) and skin. The infarctions are acute and clinicall y dramatic, whereas the calcific arteriolopathy is preexistent, having deve loped slowly, sometimes over years, and silently Separating these two proce sses facilitates analyses of pathogenetic factors, such as those that targe t subcutaneous arterioles for calcification and those that interfere with b lood flow through the calcified arterioles, sufficient in some patients to cause the infarctions, and of why obesity in CRF is a syndrome risk factor. This approach further helps to provide a much needed standardized definiti on of the syndrome, thereby facilitating comparisons of the results of such treatments as parathyroidectomy, anticoagulants, and phosphate binders. Fi nally, the separation shows why the application of such terms as calciphyla xis and calcifying panniculitis to this syndrome is inappropiate, (C) 2000 by the National Kidney Foundation, Inc.