Proximal cutaneous necrosis associated with small vessel calcification in renal failure.

Cutaneous necrosis with microvascular calcification is a rare and serious complication of chronic renal failure and has been given the sobriquet of 'calciphylaxis'. We describe four dialysis-dependent patients with proximal cutaneous necrosis who presented with this distinctive clinical syndrome. All of the patients were women aged between 40 and 68, and all developed widespread livedo reticularis followed by painful subcutaneous nodules which progressed to eschar-like lesions of the skin. Microvascular calcification was seen on radiographs of the limbs, especially at the sites of the cutaneous lesions. Serum phosphorus concentrations were increased in all the patients (maximally to between 2 and 3.6 mmol/l), but serum calcium concentrations were mildly increased in only two patients and only one patient had hyperparathyroidism. Histological examinations of skin biopsies in two patients showed cutaneous infarcts. Three patients died despite a reduction in serum phosphorus concentration and one patient improved. The proximal form of 'calciphylaxis' constitutes a distinct syndrome which can be recognized clinically.