Calciphylaxis presenting with calf pain and plaques in four continuous ambulatory peritoneal dialysis patients and in one predialysis patient.

Calciphylaxis is a rare disease associated with hemodialysis or transplantation, high parathyroid hormone values, and increased serum calcium x phosphate (Ca x P) product. Only four patients on continuous ambulatory peritoneal dialysis have been reported with this condition. We report five cases presenting within a 2-year period with severe calf pain and tenderness with extensive nonulcerating large, hard, and tender subcutaneous plaques in the calves. Calcium deposition was confirmed radiologically and by bone scanning. Four patients were on continuous ambulatory peritoneal dialysis, and the other was not yet on dialysis. High serum Ca x P product was found in three of these patients at onset of the condition. Two patients had normal parathyroid hormone levels at onset. Calcium salts and/or calcitriol had been taken prior to onset in three patients. When presenting in this fashion, the diagnosis can be easily made by the uniqueness of the physical findings in the legs. Our observation suggests that the condition should no longer be considered rare and is not confined to hemodialysis patients. Furthermore, it can occur in predialysis patients.