Polyarteritis nodosa

Description, Causes and Risk Factors:

Abbreviation: PAN.

Alternative Name: Kussmaul disease, periarteritis nodosa.

Polyarteritis nodosa is a multisystem, necrotizing vasculitis of small and medium-sized muscular arteries. The organ systems commonly involved are kidneys, heart, liver and gastrointestinal tract. It does not involve pulmonary arteries.

Polyarteritis nodosa is a disease of unknown cause that affects arteries, the blood vessels that carry oxygenated blood to organs and tissues. It occurs when certain immune cells attack the affected arteries. Some research has linked it to the presence of microscopic clumps of antibodies from the body's defense system, coupled with foreign proteins, such as portions of a virus. In some people with polyarteritis nodosa, the illness seems to be triggered by a viral liver infection, either hepatitis B or hepatitis C.

In some patients, researchers have found at least one autoantibody (an immune protein that attacks the body rather than a foreign invader) that appears to be related to the arterial damage of polyarteritis nodosa. This autoantibody, called antineutrophil cytoplasmic antibody, also has been found in the blood of patients with other vasculitic disorders, including Wegener's granulomatosis. However, most patients with polyarteritis nodosa do not have this antibody in their blood or tissues, and many experts do not believe this antibody plays an important role in this condition.

The disease occurs more commonly in adult males than females (3:1). Peak incidence 4'th and 5'th decades. No familial distribution or particular human leukocyte antigen (HLA).

Symptoms:

Generalized symptoms may include:

Fever.

• Fatigue.

• Weakness.

• Loss of appetite.

• Weight loss.

• Muscle and joint aches are common.

• The skin may show rashes, swelling, ulcers, and lumps.

• Peripheral neuropathies are very common (50 to 70%). This includes tingling, numbness and/or pain in the hands, arms, feet, and legs.

• Central nervous system (CNS) lesions may occur 2 to 3 years after the onset of PAN and may lead to cognitive dysfunction, decreased alertness, seizures and neurologic deficits.

• Skin abnormalities are very common in PAN and may include purpura, livedo reticularis, ulcers, nodules or gangrene.

• Skin involvement occurs most often on the legs and is very painful.

Diagnosis:

There are no specific lab tests for diagnosing polyarteritis nodosa. Diagnosis is based on the physical examination and a few laboratory studies that help to confirm the diagnosis. Tests may include:

Complete blood count, looking for evidence of anemia, which is common in polyarteritis nodosa, or other abnormal blood counts, which may be found in infections or lupus.

• Erythrocyte sedimentation rate, a measure of body-wide inflammation, commonly elevated in patients with vasculitis.

• Blood chemistry to measure levels of blood urea nitrogen and creatinine, two chemicals that reflect kidney function.

• Urinalysis, which is a microscopic examination of urine, to check for kidney damage or inflammation.

• Blood tests to check for hepatitis B or hepatitis C infection.

• A blood test for the antineutrophil cytoplasmic antibody (ANCA).

Treatment:

Polyarteritis nodosa is a serious illness that can be fatal. Treatment is directed toward decreasing the inflammation of the arteries by suppressing the immune system. Medications used to treat polyarteritis nodosa may include intravenous and oral cortisone medications such as prednisone, as well as immunosuppressive drugs such as cyclophosphamide (Cytoxan) or azathioprine (Imuran).

When hepatitis B is present in patients with polyarteritis nodosa, antiviral medications (such as vidarabine and interferon-alpha) are used as primary treatments. Some studies have used various combinations of antiviral medications, plasma exchange, and immunosuppressive drugs.

Risks and benefits of drugs must be carefully discussed with your PCP.

NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.