Case Presentation: A 68 year-old female with history of diabetes mellitus, chronic kidney disease, morbid obesity, and pulmonary embolism on Warfarin presented with shortness of breath and anasarca. Initial labs showed acute kidney injury (Creatinine 8.11 mg/dL, compared to baseline 3.0-3.2 mg/dL). After failing diuresis, hemodialysis (HD) was started. Two weeks after HD initiation, patient complained of worsening pain to her lower extremities. Labs showed: PTH 380 pg/mL, phosphorus 8.0 mg/dL, and corrected calcium 10.7 mg/dL. Physical exam revealed multiple indurated plaques with an erythematous rim and a necrotic desquamating center throughout both thighs and calves. Biopsy taken showed microthrombi; however, no frank microcalcifications were seen with Von Kossa stain. Collectively, these findings suggested early calciphylaxis.

Due to worsening eschar and pain, she underwent surgical wound debridement. Final biopsy of eschar showed gangrenous necrosis with diffuse calcium deposition, compatible with calciphylaxis. Sevelamer and sodium thiosulfate (STS) were promptly added. Although patient reported initial improvement with treatment, she suffered multiple readmissions for wound infections and ultimately expired from septic shock.

Discussion: Calcific uremic arteriolopathy (CUA), calciphylaxis, is a rare but potentially fatal vasculopathy  seen commonly in end-stage renal disease (ESRD) patients on HD; other risk factors include Warfarin use, diabetes, obesity, dysregulation of calcium-phosphorus metabolism. Its pathogenesis is poorly understood, but is believed to involve extensive vascular injury inciting ischemia and end-organ dysfunction. Although typically seen in patients on HD for over 1-2 years, there are case reports of accelerated onset within months of HD initiation, and even in those with renal insufficiency not on HD. Management hinges on optimization of serum calcium and phosphorus levels, hyperbaric oxygenation, and/or treatment of underlying hyperparathyroidism if present. In recent years, sodium thiosulfate (STS) is emerging as a viable treatment. Our case highlights a rare phenomenon that requires a high index of suspicion, especially given our patient’s rapid onset of CUA shortly after HD initiation. It also features the relatively novel use of STS in CUA, for which data is sparse; and underlines the need for further investigation on other treatment modalities in this crippling disorder.

Conclusions: Calciphylaxis is a rare disorder that requires providers to have greater index of suspicion, as early intervention is pivotal for favorable outcome. Our case features an accelerated onset of CUA within weeks of HD, and the use of STS as treatment. Most importantly, it underlines the need for increased awareness of CUA when considering painful skin lesions amongst at-risk patients.