Polyarteritis Nodosa

Medically Reviewed by Stephanie S. Gardner, MD on April 26, 2022
5 min read

Polyarteritis nodosa (PAN) is a rare disease that makes your blood vessels swell. It can affect the blood vessels that go to almost every part of your body, including your heart, kidneys, and intestines. It could keep your organs from getting enough blood.

PAN is very treatable, especially if it's caught early. Medication can protect your blood vessels from damage and help with your symptoms.

Polyarteritis nodosa can affect many organ systems. Some of the most common ones are your skin, peripheral nerves (nerves other than your brain and spinal cord), intestinal tract, kidneys, heart, and joints.

If you have PAN, you may have a wide range of symptoms, including:

Depending on which organs are affected, you might also have:


Joints and muscles


Digestive tract


  • Numbness or tingling in your arms, hands, legs, and feet
  • Seizures
  • Weakness in your hands or feet

Skin (often on your legs)

  • Bumps
  • Changes in skin color
  • Purple spots, called purpura
  • Rash
  • Sores


  • Swelling in the white part of your eye

Genitals (in men)

  • Painful or tender testicles


PAN is an autoimmune disease. Your immune system mistakes your blood vessels for a virus or other foreign invader and attacks them. This makes them inflamed, a condition called vasculitis.

When a blood vessel is inflamed, it swells and stretches. Its walls get thinner and thinner, like a balloon. This is called an aneurysm. Eventually, the blood vessel walls can stretch so much that they burst.

Swelling can also narrow blood vessels. Blood doesn't have enough room to move through them. When that happens, less blood gets to your organs.

Most of the time, doctors don't know what causes this immune attack. In a small number of people, it may be triggered by hepatitis B or hepatitis C. Other infections, like strep or staph, might also cause PAN.

Most people who have PAN get it in their 40s or 50s, but it can affect people of all ages. Men are more likely than women to get it.

PAN is a complicated disease. You might need several tests to get a proper diagnosis. Part of the process involves ruling out other types of diseases that might cause similar symptoms or affect two or more systems in your body.

Your doctor will ask about your symptoms and give you a physical exam. They may also order tests, including:

  • Blood or urine tests to see how well your kidneys and other organs work and to find out if you've been infected with hepatitis B or C.
  • Imaging tests to look for damage to your blood vessels or organs.
    • X-ray. This uses radiation in low doses to make images of things inside your body.
    • CT scan. Powerful X-rays from different angles are put together to make detailed pictures of the inside of your body.
    • MRI. This uses powerful magnets and radio waves to make pictures.
  • An arteriogram (also called an angiogram), usually for blood vessels to your intestines or kidneys. Your doctor injects a dye into your bloodstream. An X-ray of your blood vessels looks for problem areas.
  • A biopsy to show if there's swelling in your blood vessels. Your doctor will take a small piece of tissue from the wall of a blood vessel and check it under a microscope for signs of PAN.

Getting treatment as soon as possible can protect your blood vessels and put PAN into remission, which is when you don't have any signs of the disease.

You'll take medicine to stop your immune system from attacking your blood vessels and to bring down swelling. These might include:

  • Corticosteroids, such as prednisone or prednisolone
  • Immunosuppressive drugs. If your PAN is very serious, you also might get a drug like cyclophosphamide (Cytoxan), methotrexate (Trexall), or azathioprine (Imuran) to help calm your immune system. Once your symptoms get better, your doctor will lower your dose of medicines. Eventually, you should be able to stop taking them.
  • Antiviral medications if you have hepatitis B or C

If you have high blood pressure, you'll take medication for that, too.

PAN can cause different types of complications, depending on the part of the body or system affected.

  • Brain and spinal cord (central nervous system). You may have problems with attention, memory, and processing information, along with seizures, problems with alertness, and other issues. These problems can happen 2 to 3 years after first getting PAN. Damage to your brain could also lead to a stroke.
  • Kidneys. After some time, you might need dialysis.
  • Heart. PAN may cause a heart attack or congestive heart failure.
  • Digestive tract. Rarely, you may have damaged or dead tissue in your bowel (infarction) or a hole in your bowel (perforation).

Doctors estimate that 80% of people who have PAN live at least 5 years after their diagnosis. Your outlook depends on how severe your illness is and how quickly you get treatment. Even if you have a serious case, you may do well if you get treatment right away and get careful monitoring by a doctor who understands the disease.

Of people who go into remission, about 10% to 40% will have a relapse of PAN. They may have the same symptoms as before or different ones. Report any new problems to your doctor right away, and get regular checkups.