Three days after coronary angiography, a 68-year-old man develops livedo reticularis over the feet, gangrene of two toes, rising creatinine, eosinophilia of 1500/mm3, and low serum complement. The pathogenetic basis of these findings is:

• A Type III hypersensitivity to radiocontrast media
• B ANCA-mediated necrotizing inflammation of digital arterioles
• C Embolic occlusion of small arteries by cholesterol crystals released from disrupted atheromatous plaques ✓
• D Thrombotic microangiopathy due to endothelial injury by heparin antibodies

Explanation

Cholesterol crystal embolism follows instrumentation of the aorta, when plaque disruption showers birefringent cholesterol crystals into small downstream arteries, provoking a foreign body reaction with livedo reticularis, blue toes, renal failure, eosinophilia, and hypocomplementemia. The triad of recent arterial procedure, eosinophilia, and low complement separates it from ANCA vasculitis, where complement is typically consumed variably and no procedural trigger exists, killing the best distractor.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.