Two hours after femoral artery catheterization for coronary angioplasty, a 68-year-old man develops mottled bluish discoloration of both feet with livedo reticularis and worsening creatinine. Peripheral smear and labs show eosinophilia with a low erythrocyte sedimentation rate. Which mechanism explains these findings?

• A Type IV hypersensitivity reaction to the catheter material
• B Contrast induced tubular injury from hyperosmolar media
• C Disseminated intravascular coagulation consuming platelets
• D Embolic showers of cholesterol crystals from disrupted atherosclerotic plaque ✓

Explanation

Catheter manipulation can fracture atherosclerotic plaques in the aorta, releasing cholesterol crystal emboli that lodge in small distal arteries and produce the blue toe syndrome, livedo reticularis, and acute renal failure. Eosinophilia and a low or normal ESR are characteristic and help separate it from contrast nephropathy, which lacks cutaneous signs, and from DIC, which shows thrombocytopenia and abnormal coagulation studies rather than eosinophilia.

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.