Calciphylaxis

Calciphylaxis, also known as calcific uremic arteriolopathy (CUA), is a rare and serious condition characterized by the calcification of small blood vessels in the fat and skin tissues, leading to extremely painful skin lesions, blood clots, and tissue death (necrosis). The condition most commonly affects patients with end-stage renal disease (ESRD) who are on dialysis, though it can also occur in patients with earlier stages of chronic kidney disease or, rarely, in individuals with normal kidney function (non-uremic calciphylaxis). The hallmark clinical features include intensely painful, violaceous (purplish) skin lesions that progress to necrotic ulcers with dark eschars, typically affecting the trunk, thighs, buttocks, and lower extremities. The underlying pathology involves calcium deposition in the walls of small arterioles and capillaries of the dermis and subcutaneous fat, resulting in ischemia and infarction of overlying tissues. Calciphylaxis carries a very high mortality rate, estimated at 60-80% within one year of diagnosis, primarily due to sepsis from wound infections. Risk factors include female sex, obesity, diabetes mellitus, hyperparathyroidism, elevated calcium-phosphate product, use of warfarin, and vitamin K deficiency. The condition affects the integumentary system (skin), vascular system, and can have systemic consequences including secondary infections and multi-organ dysfunction. Diagnosis is often clinical but may be confirmed by skin biopsy showing medial calcification of dermal arterioles with intimal proliferation and thrombosis. Treatment is multidisciplinary and includes wound care, pain management, correction of calcium and phosphate imbalances, and discontinuation of potential contributing medications such as warfarin and calcium-based phosphate binders. Sodium thiosulfate, administered intravenously, has emerged as a key therapeutic agent and is widely used despite limited randomized controlled trial data. Intensification of dialysis, parathyroidectomy in cases of severe hyperparathyroidism, and hyperbaric oxygen therapy are additional treatment options. Despite these interventions, outcomes remain poor, and early recognition and aggressive management are critical to improving survival.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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