Calcyphilaxis | calciphic uremic arteriolopathy

đź’ˇ
Severe, sometimes fatal disorder
  • Mechanism
    • Metastatic calcification in blood vessels
    • Cutaneous ischemia and necrosis
  • Etiology: due to disturbances in calcium homeostasis
    • 2 major forms
      • Uremic (end stage renal disease, on hemodyalisis, with secondary hyperparathyroidism)
      • Non-uremic (other medical conditions or medications)
        • Warfarin, high dose steroids
        • Primary hyperparathyroidism
        • Ectopic PTH secretion by carcinoid tumor
        • Vitamin D intoxication
  • Fatores de risco
    • hypercoagulability: underlying protein C disfunction, antiphospholipid antibodies
    • obesity
  • Clinical presentation
    • Markedly painful retiform purpura and ulcerations
    • Cutaneous and subcutaneous calcifications - plaques or nodules
      • Underlying hard, stone-like induration
    • Distribution Sometimes linear
    • Sometimes retiform purpura/livedoid appearance
    • PAIN
    • Reticulated violaceous plaques with central necrosis or echar
    • Sometimes, retiforme purpura or bullae precede the ulceration
  • Exames complementares de diagnĂłstico
    • Ca*PO4 product may be elevated
    • Can use imaging (XRay, CT, U/S or scintigraphy), if biopsy unobtainable
      • Review of recently performed radiology may uncover “missed” diagnoses
  • Histology
    • PadrĂŁo vasculopático
    • Calcification of vessel walls leading to ischemia
    • Ischemic fat necrosis and mixed cell infiltrate
    • Calcium deposits visible with Von Kossa
    • Deposits of calcium within blood vessel walls of the subcutis usually present on skin biopsy
  • Tratamento
    • TOC: IV Sodium thiosulfate (chelator) 25g 3x/semana, continued for 2 months after healing
  • Treatment
    • Avoid warfarin and prednisone → known triggers
    • Low calcium dialysis
    • Phosphate binders
    • Parathyroidectomy
    • Aggressive wound care
    • Sodium thiosulfate local injections
    • Pamidronate
    • Cinacalcet
    • Apixaban
  • 1 year mortality ~50% → poor prognosis