Calciphylaxis mimicking dermatomyositis: ischemic myopathy complicating renal failure

BACKGROUND: Among the complications of chronic renal failure is a syndrome of medial calcification of small- to medium-sized arteries associated with ischemic necrosis of the skin and other organ systems, leading to gangrene and a poor prognosis. The syndrome has been reviewed in the renal, dermatologic, and surgical literature under the term calciphylaxis, which describes a postulated pathogenetic mechanism whereby sensitization to an endogenous or exogenous substance (such as parathyroid hormone) predisposes to calcium deposition after exposure to a challenging agent. Myopathy has rarely been reported as the presenting feature, and the syndrome has not been discussed in the neurologic literature. METHODS: We report two patients with renal failure and systemic calciphylaxis who presented to our hospital with myopathic complaints and signs suggesting dermatomyositis. We also discuss possible disease mechanisms and treatment. CONCLUSIONS: Because early treatment (including aggressively lowering the calcium and phosphate levels and parathyroidectomy) may improve the outcome, early recognition of the syndrome of calciphylaxis is essential.