Cutaneous calcification in patients with kidney disease is not always calciphylaxis.

Calciphylaxis, also referred to as calcific uremic arteriolopathy, is a rare disorder that predominantly afflicts patients with end-stage renal disease. In this issue of Kidney International, a report describing histologic features of calciphylaxis questions the specificity of histologic findings typically considered to be characteristic of calciphylaxis. Validated diagnostic criteria are much needed for the clinical care and the investigational studies of patients with calciphylaxis.