A skin lesion after cardiac catheterization.

A 64-year-old man with diabetes and hypertension presented with a 2-day history of sudden onset of acute pain and cyanosis on the sole of his right foot 4 days after undergoing cardiac catheterization and coronary angiography. The physical examination revealed macular, violaceous, connecting rings in a net-like pattern that blanched with pressure and disappeared when the foot was elevated, a presentation compatible with livedo reticularis (Figure 1). Laboratory testing (complete blood cell count, biochemistry panel, coagulation test, and C-reactive protein test) was notable only for eosinophilia. A few days later, the patient returned with abdominal pain, diarrhea, and acute renal injury with urinary eosinophils (7% of the white blood cells in the urine) and proteinuria. Q: Which is the most likely diagnosis? □ Infective endocarditis □ Pernio (chilblain) □ Cholesterol crystal embolism □ Cutaneous small-vessel vasculitis