Overview of Vasculitis

ByAlexandra Villa-Forte, MD, MPH, Cleveland Clinic
Reviewed/Revised Dec 2024
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Vasculitic disorders are caused by inflammation of the blood vessels (vasculitis).

  • Vasculitis can be triggered by certain infections or medications or can occur for unknown reasons.

  • People may have general symptoms, such as fever or fatigue, followed by other symptoms depending on which organs are affected.

  • To confirm the diagnosis, a biopsy is done on a sample of tissue from an affected organ to detect inflammation in the blood vessels.

  • Corticosteroids and other drugs that suppress the immune system are often used to reduce inflammation and relieve symptoms.

Vasculitis can affect people of all ages, but some types are more common among certain age groups.

Vasculitis may affect arteries (large, medium, or small), capillaries, veins, or a combination. It may affect a whole blood vessel or only part of it. It may affect blood vessels that supply one part of the body, such as the head, nerves, or skin; or blood vessels that supply many different organs (called systemic vasculitis). Any organ system can be affected. Sometimes vasculitis affects the skin but not the internal organs (cutaneous vasculitis).

Cutaneous Vasculitis
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This image shows multiple purple bruises (ecchymoses) and blotches (purpura) on the legs.
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Causes of Vasculitis

Usually, what triggers vasculitis is unknown. In these cases, the vasculitis is known as primary vasculitis. However, when infections, toxins, certain viruses (especially hepatitis viruses), and medications trigger the disorder, it is known as secondary vasculitis.

Vasculitis may result from cancer or another disorder that causes inflammation. Presumably, the inflammation occurs when the immune system mistakenly identifies blood vessels or parts of a blood vessel as foreign and attacks them. Cells of the immune system, which cause inflammation, surround and infiltrate the affected blood vessels, damaging them. The damaged blood vessels may become leaky, narrow, or clogged. As a result, blood flow to the tissues supplied by the damaged vessels is disrupted. The tissues deprived of blood (ischemic areas) can be permanently damaged or die.

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Symptoms of Vasculitis

Symptoms of vasculitis may result from direct damage to the blood vessels or from indirect damage to tissues (such as nerves or organs) whose blood supply has been disrupted or reduced (ischemia).

Symptoms vary depending on the size and location of the affected blood vessels and the degree of damage caused to the affected organs. For example, the following may occur:

  • Skin: A rash of bluish purple to brown spots (hemorrhages) or blotches (purpura), hives, small bumps (nodules), tiny spots (petechiae), mottled discoloration caused by dilated surface blood vessels (livedo reticularis), or sores (ulcers) on the lower legs

  • Peripheral nerves: Numbness, tingling, or weakness in the affected limb

  • Brain: Confusion, seizures, and strokes

  • Digestive tract: Abdominal pain, diarrhea, nausea, vomiting, and blood in the stool

  • Heart: Angina and heart attacks

  • Lungs: Shortness of breath, coughing (sometimes bloody), wheezing

  • Kidneys: High blood pressure, retention of fluid (edema), and kidney dysfunction

  • Joints: Joint pain or swelling

Livedo Reticularis
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This photo shows the lacy red pattern on the skin that is typical of livedo reticularis.
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Inflammation can also cause general symptoms such as fever, night sweats, fatigue, muscle aches, loss of appetite, and weight loss.

Vasculitis can cause serious complications that require immediate treatment. For example, damaged blood vessels in the lungs, brain, or other organs may bleed (hemorrhage). Effects on the kidneys may progress rapidly, leading to kidney failure. Eye problems may result in blindness.

Diagnosis of Vasculitis

  • A doctor's evaluation

  • Blood and urine tests

  • Tissue biopsy (for confirmation of diagnosis)

  • Sometimes imaging tests

Vasculitis is often not suspected when symptoms first develop because it is uncommon, and most of its symptoms are caused much more often by other disorders. Nonetheless, certain combinations of symptoms or the persistence of symptoms eventually leads doctors to suspect vasculitis.

The following blood and urine tests are usually done:

  • Complete blood count: Abnormalities, such as lower counts of red blood cells (anemia), too many platelets, too many white blood cells, or a high proportion of certain kinds of white blood cells, can occur in vasculitis but also in many other disorders. Vasculitis may cause anemia by decreasing the body’s production of red blood cells or by causing internal bleeding.

  • Comprehensive metabolic panel: This blood test measures substances that, when abnormal, can indicate significant damage to the kidneys or liver. The kidneys and liver are organs that are affected in various types of vasculitis.

  • Antibody tests: Depending on what disorder is suspected, blood is analyzed for certain antibodies (such as antineutrophil cytoplasmic antibodies) and complement proteins. For example, antineutrophil cytoplasmic antibodies are usually present in people who have granulomatosis with polyangiitis or microscopic polyangiitis.

  • Infection tests: Blood tests may be done to check for infections (such as hepatitis B and hepatitis C) that may have triggered the vasculitis.

  • Inflammation tests: Blood tests are done to estimate the degree of inflammation, which vasculitis usually causes. For example, how quickly red blood cells (erythrocytes) drop to the bottom of a test tube (erythrocyte sedimentation rate, or ESR) is measured. A fast rate suggests inflammation. High levels of C-reactive protein (which the liver produces in response to bodywide inflammation) also suggest inflammation. However, inflammation has many causes other than vasculitis.

  • Urine test: A sample of urine is tested for red blood cells and protein. The results of this test can help doctors determine whether the kidneys are affected. This information is important because kidney inflammation can cause severe damage before symptoms develop.

Lab Test

Blood and urine test results may help in making the diagnosis but are usually not conclusive. For confirmation, a sample of tissue from an affected organ is usually removed and examined under a microscope (biopsy) for signs of vasculitis. For skin biopsies, an anesthetic is used to numb the area (local anesthetic), and biopsy can often be done on an outpatient basis.

Occasionally, an imaging test of the blood vessels (such as arteriography or computed tomography [CT] or magnetic resonance angiography) can be done instead of a blood vessel biopsy. Other imaging tests may be needed. For example, if the lungs seem to be affected, a chest x-ray is done, and doctors may also do a CT scan.

Some tests may be done to exclude other disorders that can cause similar symptoms.

Prognosis for Vasculitis

The prognosis depends on the type and severity of vasculitis and the organs that are affected. If the kidneys or heart is affected, the prognosis tends to be worse.

Treatment of Vasculitis

  • Treating obvious cause of vasculitis (including stopping certain medications)

  • Corticosteroids and other immunosuppressants

If a cause is evident, it is treated. For example, if the vasculitis is caused by an infection, treating the infection treats the vasculitis. Medications that are causing the vasculitis are stopped. Other treatment depends on the type and severity of the vasculitis and the organs that are affected. Typically, such treatment aims to stop the immune system from continuing to damage blood vessels.

Mild types of vasculitis, such as those that affect only the skin, may require little treatment, possibly only close monitoring or treatment of the symptoms.

People should learn as much as they can about their disorder so that they can report any major symptoms to their doctor promptly. Learning about the side effects of the medications being used is also important. People, even when in remission, should keep in touch with their doctor because how long remission will last cannot be predicted.

Corticosteroids and other immunosuppressants

Once inflammation is controlled (called remission), all medications may be stopped. Some people remain in remission indefinitely. In other people, symptoms return one or more times (called a relapse). If relapses occur often, people may need to take an immunosuppressant indefinitely. Some people have to take corticosteroids for a long time.

Side effects, such as decreased bone density (osteoporosis), an increased risk of infections, cataracts, high blood pressure, weight gain, and diabetes, are more likely to occur when corticosteroids are taken for a long time. To help prevent decreased bone density, people are advised to take calcium and vitamin D

Immunosuppressants weaken the immune system, so the risk of developing serious infections and other side effects is increased. All people treated with these immunosuppressants should be monitored for opportunistic and other infections. Testing for prior infection with tuberculosis (TB) and hepatitis B should be considered because both can be reactivated by immunosuppressants. Routine vaccinations (for example, for influenza and pneumonia) are recommended and extremely important for people who take immunosuppressants.

cyclophosphamidecyclophosphamide on the bladder, is also given. A complete blood count is done frequently, at least every 2 weeks, when people are on intravenous cyclophosphamide, and sometimes weekly when people are taking oral cyclophosphamide.

People should learn as much as they can about their disorder so that they can report any major symptoms to their doctor promptly. Learning about the side effects of the medications being used is also important. People, even when in remission, should keep in touch with their doctor because how long remission will last cannot be predicted.

More Information

The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.

  1. Vasculitis Foundation: Provides information for people with vasculitis, including how to find a doctor, learn about research studies, and join patient advocacy groups

Drugs Mentioned In This Article

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