['Calciphylaxis, historically considered rare, seems to be increasing in frequency. In our single center, 36 new cases have accumulated in seven years. The majority of these cases were non-ulcerating, which we believe to be early disease, in contradistinction to the vast majority of published cases that presented with ulcers.', 'Prospective data were collected on all patients with calciphylaxis. As well, a case control study, with two controls per patient, was performed on patients presenting with non-ulcerating plaques.', 'The incidence of calciphylaxis in dialysis patients increased with a rate of 4.5/100 patient-years in the past three years. Eighty percent of cases presented with non-ulcerating subcutaneous plaques in the calves, easily confused with cellulitis. In those patients presenting with plaques only, the mortality rate was 33% at six months. Once ulceration develops, the mortality rate increased to above 80%. Bone scan was positive in 97% of patients. Steroid therapy appeared to be beneficial in some patients. Peritoneal dialysis, female sex and diabetes were risk factors. In the case control study of patients presenting with plaques only, serum phosphate (OR 2.6; 95% CI 1.05 to 6.45, P = 0.038) and Ca x P product (OR 1.46; 95% CI 1.02 to 20, P = 0.038) predicted the disease, as did being on calcium salts + vitamin D (OR 4.05; 95% CI 1.14 to 14.5, P = 0.03).'] Is calciphylaxis usually non-ulcerating : risk factors , outcome and therapy?