A 47-year-old man has four months of weight loss, postprandial abdominal pain, livedo reticularis over the lower limbs, and newly diagnosed hypertension. There are multiple painless skin and soft tissue nodules along nerve distributions. Creatinine is 1.0 mg/dL, urinalysis is bland, and ANCA testing is negative. Catheter angiography shows multiple 2 to 5 mm aneurysmal dilatations of the renal and mesenteric arteries. Hepatitis B surface antigen is positive. What is the diagnosis?

• A Microscopic polyangiitis with renal-limited disease
• B Polyarteritis nodosa secondary to hepatitis B infection ✓
• C Thromboangiitis obliterans (Buerger disease)
• D IgA vasculitis (Henoch-Schonlein purpura)

Explanation

Polyarteritis nodosa is a necrotising inflammation of medium-sized muscular arteries, classically hepatitis B related in endemic settings, producing microaneurysms on visceral angiography. The combination of abdominal pain, hypertension from renal artery involvement, livedo, and mononeuritis multiplex with a bland urine and normal creatinine is characteristic. Microscopic polyangiitis is a small-vessel ANCA-associated disease causing pauci-immune glomerulonephritis, which this patient's bland urinalysis argues against.

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

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Written and medically reviewed by the StethoPrep medical team.