Calciphylaxis — SCE Dermatology MCQ

Correct answer: C — Sodium thiosulfate IV (25 g IV three times weekly during dialysis) alongside wound care, pain management, and addressing calcium-phosphate metabolism

Option C, sodium thiosulfate IV (25 g IV three times weekly during dialysis) alongside wound care, pain management, and addressing calcium-phosphate metabolism, is correct because calciphylaxis (calcific uraemic arteriolopathy) is a medical emergency with mortality around 60 to 80 percent at one year, and sodium thiosulfate is the mainstay pharmacological therapy. It works by chelating calcium into soluble complexes and has antioxidant, vasodilatory properties that promote dissolution of vascular calcium deposits, directly targeting the pathological arteriolar calcification causing the retiform purpura and eschar. Given during or after each haemodialysis session, it is combined with meticulous wound care (avoiding aggressive debridement of borderline tissue), opioid-based pain control for the severe ischaemic pain, and correction of calcium-phosphate metabolism (stopping calcium-based binders and vitamin D analogues, controlling secondary hyperparathyroidism, considering cinacalcet or parathyroidectomy). This multimodal approach reflects that no single intervention reverses calciphylaxis; thiosulfate is the agent-specific first-line addition to supportive care. Why the other options are wrong: E. Compression therapy: compression risks worsening ischaemia and tissue necrosis in already compromised, poorly perfused skin and is not part of standard calciphylaxis management. D. Topical corticosteroids: they do not address the underlying vascular calcification or systemic calcium-phosphate derangement and have no established role in calciphylaxis. B. Debridement alone: aggressive surgical debridement without concurrent thiosulfate and metabolic correction can extend wounds and precipitate sepsis, a leading cause of death in calciphylaxis; debridement is adjunctive, not curative or first-line alone. A. Oral antibiotics only: antibiotics treat secondary infection but do nothing for the primary arteriolar calcification and ischaemic necrosis driving the disease, so they cannot be first-line monotherapy. Key point: In calciphylaxis, IV sodium thiosulfate given peri-dialysis, combined with wound care, analgesia, and correction of calcium-phosphate/parathyroid abnormalities, is the first-line multimodal treatment, not any single supportive measure alone.

Reference: DermNet NZ, Calciphylaxis, https://dermnetnz.org/topics/calciphylaxis