Polyarteritis Nodosa

Polyarteritis Nodosa

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Medical Author: William C. Shiel Jr., MD, FACP, FACR

• What is polyarteritis nodosa?
• How is polyarteritis nodosa diagnosed?
• How is polyarteritis treated?
• Polyarteritis Nodosa At A Glance

What is polyarteritis nodosa?

Polyarteritis nodosa is a rare autoimmune disease (immune system attacking its own body) featuring spontaneous inflammation of the arteries (arteritis). Because arteries are involved, the disease can affect any organ of the body. The most common areas of involvement include the muscles, joints, intestines (bowels), nerves, kidneys, and skin. Poor function or pain in any of these organs can be a symptom. Poor blood supply to the bowels can cause abdominal pain, local bowel death, and bleeding. Fatigue, weight loss, and fever are common.

Polyarteritis nodosa is most common in middle-age people. Its cause is unknown, but it has been reported after hepatitis B infection. Polyarteritis is not felt to be an inherited condition.

How is polyarteritis nodosa diagnosed?

The diagnosis is supported by tests that indicate inflammation including elevation of blood sedimentation rate and C-reactive protein. The white blood cell count and platelet count can be elevated, while the red blood count is decreased (anemia). Hepatitis B virus testing (for either antigen and antibody) can be found in 10%-20% of patients with polyarteritis nodosa. Urine testing can show protein and red blood cells in the urine. In patients with nerves affected, nerve function tests are abnormal.

The diagnosis of polyarteritis nodosa is confirmed by a biopsy of involved tissue that reveals the inflamed blood vessels (vasculitis). Examples of tissues that are sometimes biopsied include nerves, muscle, kidneys, and bowel. Vasculitis of the bowel and kidneys can often be detected with an angiogram (x-ray testing while contrast "dye" is infused into the blood vessels).

The American College of Rheumatology established criteria for the classification of polyarteritis nodosa in 1990. For classification purposes, a patient is said to have polyarteritis nodosa if at least three of the following 10 criteria are present:

1. Weight loss greater than/equal to 4 kg
   
   
2. Livedo reticularis (a mottled purplish skin discoloration over the extremities or torso)



3. Testicular pain or tenderness (occasionally, a site biopsied for diagnosis)



4. Muscle pain, weakness, or leg tenderness
   
   
5. Nerve disease (either single or multiple)



6. Diastolic blood pressure greater than 90mm Hg (high blood pressure)
   
   
7. Elevated kidney blood tests (BUN greater than 40 mg/dl or creatinine greater than 1.5 mg/dl)



8. Hepatitis B virus tests positive (for surface antigen or antibody)
   
   
9. Arteriogram (angiogram) showing the arteries that are dilated (aneurysms) or constricted by the blood vessel inflammation
   
   
10. Biopsy of tissue showing the arteritis (typically inflamed arteries)