Polyarteritis nodosa

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Haritha Machavarapu, M.B.B.S.

Synonyms and keywords: PAN; Kussmaul disease; Kussmaul-Meier disease; periarteritis nodosa

Overview

Polyarteritis nodosa is a vasculitis of medium-sized arteries, which become swollen and damaged from attack by rogue immune cells.

Historical Perspective

Polyarteritis nodosa is also called Kussmaul disease or Kussmaul-Meier disease.

Pathophysiology

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.Inflammation starts in the vessel intima and results in fibrinoid necrosis by destroying the internal and external elastic lamina. Aneurysms and thrombi may develop at the site of lesions. One hypothesis is that this condition is caused by antibodies against HBV, via a type IIII hypersensitivity reaction.

Epidemiology and Demographics

The condition affects adults more frequently than children. It damages the tissues supplied by the affected arteries because they don't receive enough oxygen and nourishment without a proper blood supply. Polyarteritis nodosa is more common in people with hepatitis B infection.

Natural History, Prognosis, and Complications

Therapy results in remissions or cures in 90% of cases. Untreated, the disease is fatal in most cases. The most serious associated conditions generally involve the kidneys and gastrointestinal tract. Without treatment, the outlook is poor. Guillevin and coworkers have described five prognostic factors that predict high probability of mortality and are considered indications for another immunosuppressive drug in addition to prednisone.

1. Proteinuria >1g/day
2. Azotemia
3. Cardiomyopathy
4. Gastrointestinal involvement
5. Central nervous system disease

   With none of these factors, 5-year mortality is 12%. With 2 or more 5-year mortality is 46%

Complications include the following:

• Stroke
• Kidney failure
• Heart attack
• Intestinal necrosis and perforation

Diagnosis

Symptoms

• Fatigue
• Weakness
• Fever
• Abdominal pain
• Decreased appetite
• Unintentional weight loss
• Muscle aches
• Joint aches
• Skin ulcers

In this disease, symptoms result from damage to affected organs, often the skin, heart, kidneys, and nervous system.

Generalized symptoms include fever, fatigue, weakness, loss of appetite, and weight loss. Muscle and joint aches are common. Cutaneous polyarteritis nodosa most frequently manifests as nodules in the lower legs. They may not leave any residual changes but sometimes livedo reticularis is observed. Ulcerations and splinter hemorrhages are the frequent complications.

Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness.Frequently affected nerves are peroneal, median, ulnar and sural nerves. Central nervous system polyarteritis nodosa presents in three major forms : diffuse encepalopathy,focal neurological deficits and seizures. Diffuse encepahalopathy is characterised by loss of intellectual capacity, disorientation and occasionally psychosis with visual hallucinations.Cerebrovascular accidents in cerebrum, cerebellum or brain stem cause focal defecits.. Kidney involvement can produce varying degrees of renal failure.Arteritis in the renal circulation leads to hypertension.Sometimes patients present with severe flank pain because of renal infarction or rupture of intrarenal aneurysm.

Involvement of the arteries of the heart may cause a heart attack, heart failure, and inflammation of the sac around the heart (pericarditis). Vasculitis of testicular vessels can cause testicular infarction, manifesting as testicular pain or tenderness..

Abdominal pain,weight loss, food avoidance, gastrointestinal bleeding, peritonitis are seen in mesentric vasculitis.

Laboratory Studies

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

• CBC (may demonstrate an elevated white blood count)
• ESR (often elevated)
• Perinuclear pattern of antineutrophil cytoplasmic antibodies (p-ANCA) - not associated with "classic" polyarteritis nodosa, but is present in a form of the disease affecting smaller blood vessels, known as microscopic polyangiitis or leukocytoclastic angiitis.
• Tissue biopsy (reveals inflammation in small arteries, called arteritis)
• Elevated c reactive protein

Diagnostic Criteria

A patient is said to have polyarteritis nodosa if he or she has 3 of the 10 following signs:

1. Weight loss ≥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 90mmHg (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).

Diagnostic x-ray images

Images shown below are courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology

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  Polyarteritis nodosa mesenteric artery arteriogram

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  Polyarteritis nodosa liver arteriogram

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  Polyarteritis nodosa kidney arteriogram

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  Polyarteritis nodosa kidney arteriogram

Treatment

Treatment involves medications to suppress the immune system such as prednisone and cyclophosphamide. Addition of immunosuppressants like cyclophosphamide, methotrexate, azathioprine to corticosteroid therapy has better prognosis.. Patients with hepatitis B associated polyarteritis nodosa are treated with corticosteroid therapy, antiviral agents and plasma exchanges...

Mild cases of cutaneous polyarteritis nodosa are treated with nonsteroidal anti-inflammatory drugs. Severe cases are treated with corticosteroid and adjunctive therapy. Antibiotics are added to the treatment of patients with antecedent streptococcal infections or high ASO titer..

References

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