The necrotic eschar on this patient’s thigh is calciphylaxis, also known as calcific uremic arteriolopathy (CUA). Most cases are seen in ESRD and start as painful erythematous, firm lesions that progress to necrotic eschars. Up to 4% of patients with ESRD who are on dialysis develop CUA.1
The exact pathology of CUA is unknown. Calcification of the arterioles leads to ischemia and necrosis of tissue, which is not limited to the skin and can affect tissue elsewhere (eg, muscles, central nervous system, internal organs).2
Morbidity and mortality of CUA is often due to bacterial infections and sepsis related to the necrotic tissue. CUA can be treated with sodium thiosulfate (25 g in 100 mL of normal saline) infused intravenously during the last 30 minutes of dialysis treatment 3 times per week.3 Sodium thiosulfate (which acts as a calcium binder) and cinacalcet (a calcimimetic that leads to lower parathyroid hormone levels) have been used, but evidence of efficacy is limited. In a multicenter observational study involving 89 patients with chronic kidney disease and CUA, 17% of patients experienced complete wound healing, while 56% died over a median follow-up period of 5.8 months.1 (No cause of death data were available; sodium thiosulfate and a calcimimetic were the most widely used treatment strategies.) This extrapolated to a mortality rate of 72 patients per 100 individuals over the course of 1 year (the 100 patient-years rate).1
This patient continued her dialysis regimen and general care. She was seen by the wound care team and treated with topical wound care, including moist dressings for her open lesions. The eschars were not debrided because they showed no sign of active infection. Unfortunately, she was in extremely frail condition and died 1 month after evaluation.
Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.