Any organ can be affected but usually not the lungs.
Polyarteritis nodosa can be rapidly fatal or develop gradually.
Symptoms vary depending on which organ is affected.
Biopsy of an affected organ or arteriography of the blood vessels can confirm the diagnosis.
Prompt treatment with a corticosteroid, another drug that suppresses the immune system, or both is effective.
(See also Overview of Vasculitis Overview of Vasculitis Vasculitic disorders are caused by inflammation of the blood vessels (vasculitis). Vasculitis can be triggered by certain infections or drugs or can occur for unknown reasons. People may have... read more .)
Polyarteritis nodosa most often develops during middle age, usually when people are in their 50s, but it can occur at any age. It is rare.
The cause of polyarteritis nodosa is unknown, but it sometimes appears to be triggered by certain viral infections (such as hepatitis B Hepatitis B, Acute Acute hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that lasts from a few weeks up to 6 months. Hepatitis B is spread through contact with blood or other... read more or in rare cases hepatitis C Hepatitis C, Acute Acute hepatitis C is inflammation of the liver that is caused by the hepatitis C virus and that lasts from a few weeks up to 6 months. Hepatitis C is spread through contact with blood or other... read more ) or drugs. About 20% of people with polyarteritis nodosa have hepatitis B or C. Drugs may cause the disorder, but most often no trigger can be identified.
The kidneys, skin, nerves, joints, muscles, and digestive tract are most commonly affected. The liver and heart are often affected as well.
Symptoms of PAN
Polyarteritis nodosa can be mild at first but can worsen rapidly and be fatal within several months, or it can develop gradually as a chronic debilitating disease. Any organ or combination of organs can be affected. However, usually the lungs are not affected. Symptoms depend on which organs are affected and how severely they are affected. Occasionally, only one organ (such as the intestine) or a nerve is affected. At first, people may feel generally ill and tired and have a fever. They may lose their appetite and lose weight. Night sweats and generalized weakness are common symptoms.
Other symptoms occur when the arteries that carry blood to an organ are damaged, and the organ does not receive enough blood to function normally. Thus, symptoms vary depending on the organ that is affected:
Joints: Muscle pain, tenderness, and weakness; and joint pain (common) and joint inflammation (arthritis)
Digestive tract: Severe pain, bloody diarrhea, nausea, vomiting, and tears (perforations) in the intestine
Heart: Chest pain (angina Angina Angina is temporary chest pain or a sensation of pressure that occurs while the heart muscle is not receiving enough oxygen. A person with angina usually has discomfort or pressure beneath the... read more ), heart attacks Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or heart attack (myocardial infarction), depending on the location and amount... read more , and heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more
Brain: Headaches Overview of Headache A headache is pain in any part of the head, including the scalp, upper neck, face, and interior of the head. Headaches are one of the most common reasons people visit a doctor. Headaches interfere... read more , seizures Seizure Disorders In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more , and strokes Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more
Nerves: Patchy numbness Numbness Numbness refers to the partial or complete loss of sensation. It can be a symptom of nervous system malfunction. People with numbness may be unable to feel light touch, pain, temperature, or... read more , tingling, weakness Weakness Weakness refers to loss of muscle strength. That is, people cannot move a muscle normally despite trying as hard as they can. However, the term is often misused. Many people with normal muscle... read more , or paralysis in a hand or foot
Liver: Liver damage
Skin: Blue or red discoloration of the fingers or toes and occasionally skin sores
Genitals: Pain and tenderness of the testicles and inflammation in the testes (orchitis Orchitis Orchitis is infection of the testes, most often by a virus such as mumps. Orchitis is usually caused by a virus. The testis swells and is painful. A doctor's examination and urinalysis are used... read more )
Sometimes damage to an organ is irreversible, and some or all of the organ function is lost. A weakened artery may rupture, causing internal bleeding. Problems, such as a heart attack, can occur long after the inflammation has been treated.
Diagnosis of PAN
A doctor's evaluation
Polyarteritis nodosa can be difficult to diagnose. Doctors suspect polyarteritis nodosa when people have a certain combination of symptoms and blood test results. For example, doctors may suspect the diagnosis if a previously healthy middle-aged person has various combinations of symptoms such as an unexplained fever, evidence of a certain pattern of nerve damage (such as difficulty raising a foot or bending the wrist), sores on the skin, pain in the abdomen or limbs, joint or muscle pain, or rapidly developing high blood pressure.
To confirm the diagnosis of polyarteritis nodosa, doctors may take a small sample of an affected organ and examine it under a microscope (biopsy) or take x-rays of the blood vessels (arteriography Arteriography In angiography, x-rays are used to produce detailed images of blood vessels. It is sometimes called conventional angiography to distinguish it from computed tomography (CT) angiography and magnetic... read more ). For arteriography, images are recorded after a dye that is visible on x-rays (radiopaque contrast agent) is injected. Sometimes magnetic resonance angiography may be done to check for irregularities such as narrowing and dilations (aneurysms) in the wall of affected arteries. However, magnetic resonance angiography is less likely to confirm the diagnosis than angiography.
Doctors may do electromyography and nerve conduction studies Electromyography and Nerve Conduction Studies Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Electroencephalography (EEG) is a simple, painless procedure in which... read more to help select the area for a muscle or nerve biopsy.
Prognosis of PAN
Without treatment, people with polyarteritis nodosa have a less than 15% chance of surviving 5 years. With treatment, people with polyarteritis nodosa have a greater than 80% chance of surviving 5 years. People whose kidneys, digestive tract, brain, or nerves are affected have a poor prognosis.
Treatment of PAN
Treatment of symptoms or underlying cause as necessary
Treatment of polyarteritis nodosa is aimed at preventing damage from developing but often cannot reverse damage that has already occurred. Treatment depends on the severity of the disorder. Any drugs that may have triggered the disorder are stopped.
High doses of a corticosteroid, such as prednisone, can prevent polyarteritis nodosa from worsening and help people feel better. The goal is a symptom-free period (remission). Because many people need long-term treatment with a corticosteroid and because long-term treatment can have significant side effects, doctors reduce the dose once symptoms have subsided.
If the corticosteroid does not reduce the inflammation adequately, drugs that suppress the immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more (immunosuppressants), such as cyclophosphamide, may be given with the corticosteroid. Taking a corticosteroid or another immunosuppressant for a long time reduces the body’s ability to fight infections. Thus, people so treated have an increased risk of infections, which may be serious or fatal if not recognized and treated promptly.
Other treatments, such as those used to control high blood pressure, are often needed to prevent damage to internal organs.
People who have hepatitis B are treated with corticosteroids and antiviral drugs.
People who have hepatitis C and polyarteritis nodosa are treated with antiviral drugs and sometimes corticosteroids.
More Information about PAN
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Vasculitis Foundation: Provides information for patients about vasculitis, including how to find a doctor, learn about research studies, and join patient advocacy groups
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