Calciphylaxis, also known as calcific uremic arteriolopathy (CUA) or “Grey Scale”, is a rare syndrome characterized by painful skin lesions.
[2] It results in chronic non-healing wounds and indicates poor prognosis, with typical life expectancy of less than one year.
Similar extraskeletal calcifications are observed in some people with high levels of calcium in the blood, including people with milk-alkali syndrome, sarcoidosis, primary hyperparathyroidism, and hypervitaminosis D. In rare cases, certain medications such as warfarin can also result in calciphylaxis.
Widespread intravascular calcification typical of calciphylaxis lesions occur in the myocardium and prevent normal diastolic filling of the ventricles.
End-stage kidney disease patients are more likely to have vitamin K deficiency due to dietary restrictions meant to limit potassium and sodium.
[8] Reported risk factors include female sex, obesity, elevated calcium-phosphate product, medications such as warfarin, vitamin D derivatives (e.g. calcitriol, calcium-based binders, or systemic steroids), protein C or S deficiency, low blood albumin levels, and diabetes mellitus.
[9] Patients who require or have undergone any type of vascular procedures are also at increased risk for poor outcomes.
[1] The treatment of calciphylaxis requires a multidisciplinary approach, using the knowledge of nephrologists, plastic surgeons, dermatologists, and wound care specialists working together to manage the disease and its outcomes.
Indications for increasing dialysis session length or frequency include electrolyte and mineral abnormalities, such as hyperphosphatemia, hypercalcemia, and hyperparathyroidism, all of which are also risk factors for development of calciphylaxis.
However, risks include development of post-operative hungry bone syndrome (HBS), a disease state that causes low calcium and requires use of calcium supplementation and calcitriol, which should be avoided in patients with end-stage kidney disease and calciphylaxis.
The actual mechanism of the drug is unknown, but several explanations have been proposed, including chelation of calcium, vasodilation, antioxidant properties, and restoration of endothelial function.
They are most beneficial in patients who have a genetic ENPP1 deficiency and have been shown to slow development of calciphylaxis lesions in a small prospective study.
Vitamin K supplementation has also been shown to slow development of calcification in coronary arteries and the aortic valve in older patients.
The most common cause of death in calciphylaxis patients is sepsis, severe infection originating from a non-healing ulcer.
[1] Calciphylaxis most commonly occurs in patients with end-stage renal disease who are on hemodialysis or who have recently received a kidney transplant.
When reported in patients without end-stage renal disease (such as in earlier stages of chronic kidney disease or in normal kidney function), it is called non-uremic calciphylaxis by Nigwekar et al.[20] Non-uremic calciphylaxis has been observed in patients with primary hyperparathyroidism, breast cancer (treated with chemotherapy), liver cirrhosis (due to hazardous alcohol use), cholangiocarcinoma, Crohn's disease, rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE).