Polyarteritis nodosa

PAN may affect nearly every organ system and thus can present with a broad array of signs and symptoms. These manifestations result from ischemic damage to affected organs, often the skin, heart, kidneys, and nervous system. Constitutional symptoms are seen in up to 90% of affected individuals and include fever, fatigue, weakness, loss of appetite, and unintentional weight loss. ==Causes==

PAN has no association with anti-neutrophil cytoplasmic antibodies, ==Diagnosis==

No specific lab tests exist for diagnosing polyarteritis nodosa. Diagnosis is generally based on the physical examination and a few laboratory studies that help 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 three of the 10 signs known as the 1990 American College of Rheumatology (ACR) criteria, when a radiographic or pathological diagnosis of vasculitis is made: :* Weight loss greater than/equal to 4.5 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 90 mmHg (high blood pressure) :* Elevated kidney blood tests (BUN greater than 40 mg/dL or creatinine greater than 1.5 mg/dL) :* Hepatitis B (not C) 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): The sural nerve is a frequent location for the biopsy. In polyarteritis nodosa, small aneurysms are strung like the beads of a rosary, Differential diagnosis Polyarteritis nodosa rarely affects the blood vessels of the lungs, and this feature can help to differentiate it from other vasculitides that may have similar signs and symptoms (e.g., granulomatosis with polyangiitis or microscopic polyangiitis). ==Treatment==

Treatment involves medications to suppress the immune system, including prednisone and cyclophosphamide. When present, underlying hepatitis B virus infection should be immediately treated. In some cases, methotrexate or leflunomide may be helpful. Some patients have entered a remission phase when a four-dose infusion of rituximab is used before the leflunomide treatment is begun. 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. A fatal course usually involves gastrointestinal bleeding, infection, myocardial infarction, and/or kidney failure. In case of remission, about 60% experience relapse within five years. In cases caused by hepatitis B virus, however, recurrence rate is only around 6%. ==Epidemiology==

The condition affects adults more frequently than children and males more frequently than females. Most cases occur between the ages of 40 and 60. Polyarteritis nodosa is more common in people with hepatitis B infection. ==Culture==

In the 1956 American film Bigger Than Life, the protagonist character played by James Mason is diagnosed with polyarteritis nodosa after experiencing excruciating chest pain and is treated with cortisone. == References ==