(or periarteritis nodosa
) is a vasculitis
of medium-sized arteries
, which become swollen and damaged from attack by rogue immune cells
. Polyarteritis nodosa is also called Kussmaul disease
or Kussmaul-Meier disease
Causes and risk factors
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. One hypothesis is that this condition is caused by antibodies against HBV (Hepatitis B Virus), via a type III hypersensitivity reaction
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
In this disease, symptoms result from ischaemic damage to affected organs, often the skin, heart, kidneys, and nervous system.
Generalised symptoms include fever, fatigue, weakness, loss of appetite, and weight loss. Muscle and joint aches are common. The skin may show rashes, swelling, ulcers, and lumps.
Nerve involvement may cause sensory changes with numbness, pain, burning, and weakness central nervous system involvement may cause strokes or seizures. Kidney involvement can produce varying degrees of renal failure.
Involvement of the arteries of the heart may cause a heart attack, heart failure, and inflammation of the sac around the heart (pericarditis).
Signs and tests
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 (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
A patient is said to have polyarteritis nodosa if he or she has 3 of the 10 following signs known as the 1990 ACR (American College of Rheumatology) criteria:
- * Weight loss greater than/equal to 4 kg.
- * Livedo reticularis (a mottled purplish skin discoloration over the extremities or torso).
- * Testicular pain or tenderness. (occasionally, a site biopsied for diagnosis).
- * Muscle pain, weakness, or leg tenderness.
- * Nerve disease (either single or multiple).
- * Diastolic blood pressure greater than 90mmHg (high blood pressure).
- * Elevated kidney blood tests (BUN greater than 40 mg/dl or creatinine greater than 1.5 mg/dl).
- * Hepatitis B virus tests positive (for surface antigen or antibody).
- * Arteriogram (angiogram) showing the arteries that are dilated (aneurysms) or constricted by the blood vessel inflammation.
- * Biopsy of tissue showing the arteritis (typically inflamed arteries).
It should be underlined that the 1990 ACR criteria were designed for classification purposes only. Nevertheless their good discriminatory performances, indicated by the initial ACR analysis, suggested their potential usefulness for diagnostic purposes also. Subsequent studies did not confirmed their diagnostic utility, demonstrating a significant dependence of their discriminant abilities on the prevalence of the various vasculitides in the analyzed populations. Recently an original study, combining the analysis of more than 100 items used to describe patients characteristics in a large sample of vasculitides with a computer simulation technique designed to test the potential diagnostic utility of the various criteria, proposed a set of eight positively or negatively PAN discriminating items to be used a screening tool for PAN diagnosis in patients suspected of systemic vasculitis.
Treatment and Prognosis
Treatment involves medications to suppress the immune system, including prednisone
. 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.
This disease cannot be currently prevented, but early treatment can prevent some damage and symptoms.