Polyarteritis Nodosa

Key Features

Essentials of Diagnosis

• Medium-sized arteries are affected

• Clinical findings depend on the arteries involved; lungs are spared

• Common features

  • Fever

  • Abdominal pain

  • Extremity pain

  • Livedo reticularis

  • Mononeuritis multiplex

• Kidney involvement causes renin-mediated hypertension

• Associated with hepatitis B (10% of cases)

General Considerations

• A necrotizing arteritis of medium-sized vessels that has a predilection for involving the skin, peripheral nerves, mesenteric vessels (including renal arteries), heart, and brain but spares the lungs

• Rare, with a prevalence of 30 per 1 million people

• Approximately 10% of cases are caused by hepatitis B, with most cases of these occur within 6 months of onset of hepatitis B infection

Clinical Findings

Symptoms and Signs

• Fever, malaise, weight loss, and other symptoms develop over weeks to months

• Pain in the extremities

• Vasculitic neuropathy

• Livedo reticularis, subcutaneous nodules, and skin ulcers reflect involvement of deeper, medium-sized blood vessels

• Digital gangrene is not unusual

• Lower extremity ulcerations, usually occurring near the malleoli

• Renin-mediated hypertension due to involvement of renal arteries

• Acalculous cholecystitis or appendicitis caused by compromised function of major viscera

• Dramatic presentation in some cases

  • Acute abdomen caused by mesenteric vasculitis and gut perforation

  • Hypotension resulting from rupture of a microaneurysm in the liver, kidney, or bowel

• Subclinical cardiac involvement is common; overt cardiac dysfunction occurs occasionally

• Lungs are seldom (if ever) involved

Differential Diagnosis

• Microscopic polyangiitis

• Granulomatosis with polyangiitis

• Eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome)

• Endocarditis

• Cryoglobulinemia

• Cholesterol atheroembolic disease

• Other systemic causes of peripheral neuropathy

  • Rheumatoid arthritis

  • Diabetes mellitus

  • Amyloidosis

  • Sarcoidosis

  • Plasma cell myeloma

• Other causes of mesenteric ischemia, eg, embolism, atherosclerosis

Diagnosis

Laboratory Tests

• Slight anemia and leukocytosis are common

• Acute-phase reactants (ESR, CRP) are often (but not always) strikingly elevated

• Patients are ANCA-negative

• Rheumatoid factor or antinuclear antibodies may be present in low titers

• Appropriate tests for active hepatitis B infection (HBsAg, HBeAg, hepatitis B viral load) should be performed

Diagnostic Procedures

• Requires confirmation with either a tissue biopsy or vascular imaging

• Biopsies of symptomatic sites such as skin (from the edge of an ulcer or the center of a nodule) and nerve and muscle are essential for diagnosis

  • A deep biopsy, not a punch biopsy, of skin ulcers or nodules should be made to ensure a medium-size vessel is included in the sample

  • Biopsy of the nerve and muscle (instead of the nerve alone) is recommended in patients with neuropathic symptoms

  • If performed by experienced physicians, tissue biopsies normally have high benefit-risk ratios because of the importance of establishing the diagnosis

• Angiographic finding of aneurysmal dilations in the renal, mesenteric, or hepatic arteries is ...