Three days after cardiac catheterization, a 68-year-old man develops livedo reticularis over the lower limbs, bluish discoloration of several toes with intact peripheral pulses, abdominal pain, and rising serum creatinine. Peripheral smear shows eosinophilia and complement levels are low. The most likely diagnosis is:

• A Contrast-induced acute tubular necrosis
• B Heparin-induced thrombocytopenia with arterial thrombosis
• C Polyarteritis nodosa involving renal arteries
• D Cholesterol crystal embolization (atheroembolic renal disease) ✓

Explanation

Cholesterol crystal embolism follows disruption of ulcerated atherosclerotic plaques during endovascular procedures, showering cholesterol crystals into distal small arteries. Classic findings are livedo reticularis, blue toes with preserved pulses, renal failure, eosinophilia, and hypocomplementemia due to crystal-induced inflammation. Contrast nephropathy lacks cutaneous signs and eosinophilia, polyarteritis nodosa causes aneurysms and hypertension rather than post-procedure onset, and HIT presents with thrombocytopenia and thrombosis rather than livedo and eosinophilia.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.