For more information, visit http://www.nhlbi.nih.gov/health/health-topics/topics/vas/

Types of Vasculitis

There are many types of vasculitis. Each type involves inflamed blood vessels. However, most types differ in whom they affect and the organs that are involved.

The types of vasculitis often are grouped based on the size of the blood vessels they affect.

Mostly Large Vessel Vasculitis

These types of vasculitis usually, but not always, affect the body’s larger blood vessels.

Behçet's Disease

Behçet's (beh-CHET'S) disease can cause recurrent, painful ulcers (sores) in the mouth, ulcers on the genitals, acne-like skin lesions, and eye inflammation called uveitis (u-ve-I-tis).

The disease occurs most often in people aged 20 to 40. Men are more likely to get it, but it also can affect women. Behçet's disease is more common in people of Mediterranean, Middle Eastern, and Far Eastern descent, although it rarely affects Blacks.

Researchers believe that a gene called the HLA-B51 gene may play a role in Behçet's disease. However, not everyone who has the gene gets the disease.

Cogan's Syndrome

Cogan's syndrome can occur in people who have a systemic (sis-TEH-mik) vasculitis that affects the large blood vessels, especially the aorta and aortic valve. The aorta is the main artery that carries oxygen-rich blood from the heart to the body.

A systemic vasculitis is a type of vasculitis that affects you in a general or overall way.

Cogan's syndrome can lead to eye inflammation called interstitial keratitis (in-ter-STISH-al ker-ah-TI-tis). The syndrome also can cause hearing changes, including sudden deafness.

Giant Cell Arteritis

Giant cell arteritis (ar-ter-I-tis) usually affects the temporal artery, an artery on the side of your head. This condition also is called temporal arteritis. Symptoms of this condition can include headaches, scalp tenderness, jaw pain, blurred vision, double vision, and acute (sudden) vision loss.

Giant cell arteritis is the most common form of vasculitis in adults older than 50. It's more likely to occur in people of Scandinavian origin, but it can affect people of any race.

Polymyalgia Rheumatica

Polymyalgia rheumatica (POL-e-my-AL-jah RU-ma-ti-kuh), or PMR, commonly affects the large joints in the body, such as the shoulders and hips. PMR typically causes stiffness and pain in the muscles of the neck, shoulders, lower back, hips, and thighs.

PMR usually occurs by itself, but 10–20 percent of people who have PMR also develop giant cell arteritis. Also, about half of the people who have giant cell arteritis may develop PMR.

Takayasu's Arteritis

Takayasu's (tock-e-AH-sues) arteritis affects medium- and large-sized arteries, particularly the aorta and its branches. The condition sometimes is called aortic arch syndrome.

Though rare, Takayasu's arteritis mainly affects teenage girls and young women. The condition is most common in Asians, but it can affect people of all races.

Takayasu's arteritis is a systemic disease. A systemic disease is one that affects you in a general or overall way.

Symptoms of Takayasu's arteritis may include tiredness and a sense of feeling unwell, fever, night sweats, sore joints, loss of appetite, and weight loss. These symptoms usually occur before other signs develop that point to arteritis.

Mostly Medium Vessel Vasculitis

These types of vasculitis usually, but not always, affect the body’s medium-sized blood vessels.

Buerger's Disease

Buerger's disease, also known as thromboangiitis (THROM-bo-an-jee-I-tis) obliterans, typically affects blood flow to the hands and feet. In this disease, the blood vessels in the hands and feet tighten or become blocked. As a result, less blood flows to the affected tissues, which can lead to pain and tissue damage.

Rarely, Buerger's disease also can affect blood vessels in the brain, abdomen, and heart. The disease usually affects men aged 20 to 40 of Asian or Eastern European descent. The disease is strongly linked to cigarette smoking.

Symptoms of Buerger's disease include pain in the calves or feet when walking or pain in the forearms and hands with activity. Other symptoms include blood clots in the surface veins of the limbs and Raynaud's phenomenon.

In severe cases, ulcers may develop on the fingers and toes, leading to gangrene. The term "gangrene" refers to the death or decay of body tissues.

Surgical bypass of the blood vessels may help restore blood flow to some areas. Medicines generally don’t work well to treat Buerger’s disease. The best treatment is to stop using tobacco of any kind.

Central Nervous System Vasculitis

Central nervous system (CNS) vasculitis usually occurs as a result of a systemic vasculitis. A systemic vasculitis is one that affects you in a general or overall way.

Very rarely, vasculitis affects only the brain and/or spinal cord. When it does, the condition is called isolated vasculitis of the central nervous system or primary angiitis (an-jee-I-tis) of the central nervous system.

Symptoms of CNS vasculitis include headaches, problems thinking clearly, changes in mental function, or stroke-like symptoms, such as muscle weakness and paralysis (an inability to move).

Kawasaki Disease

Kawasaki (KAH-wah-SAH-ke) disease is a rare childhood disease in which the walls of the blood vessels throughout the body become inflamed. The disease can affect any blood vessel in the body, including arteries, veins, and capillaries.

Kawasaki disease also is known as mucocutaneous (myu-ko-kyu-TA-ne-as) lymph node syndrome. This is because the disease is associated with redness of the mucous membranes in the eyes and mouth, redness of the skin, and enlarged lymph nodes. (Mucous membranes are tissues that line some organs and body cavities.)

Sometimes the disease affects the coronary arteries, which carry oxygen-rich blood to the heart. As a result, a small number of children who have Kawasaki disease may have serious heart problems.

Polyarteritis Nodosa

Polyarteritis nodosa (POL-e-ar-ter-I-tis no-DO-suh) can affect many parts of the body. This disorder often affects the kidneys, the digestive tract, the nerves, and the skin.

Symptoms often include fever, a general feeling of being unwell, weight loss, and muscle and joint aches, including pain in the calf muscles that develops over weeks or months.

Other signs and symptoms include anemia (a low red blood cell count), a lace- or web-like rash, bumps under the skin, and stomach pain after eating.

Researchers believe that this type of vasculitis is very rare, although the symptoms can be similar to those of other types of vasculitis. Some cases of polyarteritis nodosa seem to be linked to hepatitis B or C infections.

Mostly Small Vessel Vasculitis

These types of vasculitis usually, but not always, affect the body’s small blood vessels.

Churg-Strauss Syndrome

Churg-Strauss syndrome is a very rare disorder that causes blood vessel inflammation. The disorder also is known as allergic angiitis and granulomatosis (GRAN-u-lo-ma-TO-sis).

Churg-Strauss syndrome can affect many organs, including the lungs, skin, kidneys, nervous system, and heart. Symptoms can vary widely. They may include asthma, higher than normal levels of white blood cells in the blood and tissues, and abnormal lumps known as granulomas (gran-yu-LO-mas).

Essential Mixed Cryoglobulinemia

Essential mixed cryoglobulinemia (KRI-o-GLOB-u-luh-NE-me-uh) can occur alone or with a systemic vasculitis. A systemic vasculitis is one that affects the body in a general or overall way.

“Cryoglobulinemia” refers to abnormal proteins in the blood. These proteins form a gel when a blood sample is exposed to temperatures lower than normal body temperature.

Symptoms often include joint aches; weakness; nerve changes, such as numbness, tingling, and pain in the limbs; kidney inflammation; and a raised, bumpy, reddish-purple skin rash known as palpable purpura (PURR-purr-ah).

Although essential mixed cryoglobulinemia can occur with other conditions, most often it’s linked to chronic hepatitis C infection.

Henoch-Schönlein Purpura

Henoch-Schönlein purpura (HSP) is a type of vasculitis that affects the smallest blood vessels in the skin, joints, intestines, and kidneys. These blood vessels are called capillaries.

Symptoms often include stomach pain, aching and swollen joints, and signs of kidney damage, such as blood in the urine. Another symptom is a bruise-like rash that mostly shows up as reddish-purple blotches on the lower legs and buttocks (although it can appear anywhere on the body).

HSP is most common in children, but it also can affect teens and adults. In children, about half of all cases follow a viral or bacterial upper respiratory infection. Most people get better in a few weeks and have no lasting problems.

Hypersensitivity Vasculitis

Hypersensitivity vasculitis affects the skin. This condition also is known as allergic vasculitis, cutaneous (ku-TA-ne-us) vasculitis, or leukocytoclastic (LU-ko-si-TOE-klas-tic) vasculitis.

A common symptom is red spots on the skin, usually on the lower legs. For people who are bedridden, the rash appears on the lower back.

An allergic reaction to a medicine or infection often causes this type of vasculitis. Stopping the medicine or treating the infection usually clears up the vasculitis. However, some people may need to take anti-inflammatory medicines, such as corticosteroids, for a short time. These medicines help reduce inflammation.

Microscopic Polyangiitis

Microscopic polyangiitis (POL-e-an-jee-I-tis) affects small blood vessels, particularly those in the kidneys and lungs. The disease mainly occurs in middle-aged people; it affects men slightly more often than women.

The symptoms often aren't specific, and they can begin gradually with fever, weight loss, and muscle aches. Sometimes the symptoms come on suddenly and progress quickly, leading to kidney failure.

If the lungs are affected, coughing up blood may be the first symptom. Sometimes microscopic polyangiitis occurs with a vasculitis that affects the intestinal tract, the skin, and the nervous system.

The signs and symptoms of microscopic polyangiitis are similar to those of Wegener's granulomatosis (another type of vasculitis). However, microscopic polyangiitis usually doesn't affect the nose and sinuses or cause abnormal tissue formations in the lungs and kidneys.

The results of certain blood tests can suggest inflammation. These results include a higher than normal erythrocyte sedimentation rate (ESR); lower than normal hemoglobin (HEE-muh-glow-bin) and hematocrit (hee-MAT-oh-crit) levels (which suggest anemia); and higher than normal white blood cell and platelet (PLATE-let) counts.

Also, more than half of the people who have microscopic polyangiitis have certain antibodies (proteins) in their blood. These antibodies are called antineutrophil cytoplasmic autoantibodies (ANCA). ANCA also occur in people who have Wegener's granulomatosis.

Testing for ANCA can't be used to diagnose either of these two types of vasculitis. However, testing can help evaluate people who have vasculitis-like symptoms.

Wegener's Granulomatosis

Wegener's granulomatosis is a rare type of vasculitis. It affects men and women equally, but it occurs more often in Whites than in African Americans. This type of vasculitis can occur at any age, but it’s more common in middle-aged people.

Wegener's granulomatosis typically affects the sinuses, nose, and throat; the lungs; and the kidneys. The condition also can affect other organs.

In addition to inflamed blood vessels, the affected tissues also develop abnormal lumps called granulomas. If granulomas develop in the lungs, they can destroy the lung tissue. The damage can be mistaken for pneumonia or even lung cancer.

Symptoms of Wegener's granulomatosis often aren’t specific. They can begin slowly with fever, weight loss, and muscle aches. Sometimes the symptoms come on suddenly and progress rapidly, leading to kidney failure. If the lungs are affected, coughing up blood may be the first symptom.

The results of certain blood tests can suggest inflammation. These results include a higher than normal ESR; lower than normal hemoglobin and hematocrit levels (which suggest anemia); and higher than normal white blood cell and platelet counts.

Another test looks for antiproteinase-3 (an antineutrophil cytoplasmic autoantibody (ANCA)) in the blood. Most people who have active Wegener's granulomatosis will have this antibody. A small portion may have another ANCA known as antimyeloperoxidase-specific ANCA.

Having either ANCA antibody isn't enough on its own to make a diagnosis of Wegener's granulomatosis. However, testing for the antibodies can help support the diagnosis in patients who have other signs and symptoms of the condition.

A biopsy of an affected organ is the best way for your doctor to make a firm diagnosis. A biopsy is a procedure in which your doctor takes a small sample of your body tissue to examine under a microscope.

Other Names for Vasculitis

• Angiitis
• Arteritis

What Causes Vasculitis?

Vasculitis occurs if your immune system attacks your blood vessels by mistake. What causes this to happen isn't fully known.

A recent or chronic (ongoing) infection may prompt the attack. Your body also may attack its own blood vessels in reaction to a medicine.

Sometimes an autoimmune disorder triggers vasculitis. Autoimmune disorders occur if the immune system makes antibodies (proteins) that attack and damage the body's own tissues or cells. Examples of these disorders include lupus, rheumatoid arthritis, and scleroderma. You can have these disorders for years before developing vasculitis.

Vasculitis also may be linked to certain blood cancers, such as leukemia and lymphoma.

Who Is at Risk for Vasculitis?

Vasculitis can affect people of all ages and races and both sexes. Some types of vasculitis seem to occur more often in people who:

• Have certain medical conditions, such as chronic hepatitis B or C infection
• Have certain autoimmune diseases, such a lupus, rheumatoid arthritis, and scleroderma
• Smoke

For more information, go to "Types of Vasculitis."

What Are the Signs and Symptoms of Vasculitis?

The signs and symptoms of vasculitis vary. They depend on the type of vasculitis you have, the organs involved, and the severity of the condition. Some people may have few signs and symptoms. Other people may become very sick.

Sometimes the signs and symptoms develop slowly, over months. Other times, the signs and symptoms develop quickly, over days or weeks.

Systemic Signs and Symptoms

Systemic signs and symptoms are those that affect you in a general or overall way. Common systemic signs and symptoms of vasculitis are:

• Fever
• Loss of appetite
• Weight loss
• Fatigue (tiredness)
• General aches and pains

Organ- or Body System-Specific Signs and Symptoms

Vasculitis can affect specific organs and body systems, causing a range of signs and symptoms.

Skin

If vasculitis affects your skin, you may notice skin changes. For example, you may have purple or red spots or bumps, clusters of small dots, splotches, bruises, or hives. Your skin also may itch.

Joints

If vasculitis affects your joints, you may ache or develop arthritis in one or more joints.

Lungs

If vasculitis affects your lungs, you may feel short of breath. You may even cough up blood. The results from a chest x ray may show signs that suggest pneumonia, even though that may not be what you have.

Gastrointestinal Tract

If vasculitis affects your gastrointestinal tract, you may get ulcers (sores) in your mouth or have stomach pain.

In severe cases, blood flow to the intestines can be blocked. This can cause the wall of the intestines to weaken and possibly rupture (burst). A rupture can lead to serious problems or even death.

Sinuses, Nose, Throat, and Ears

If vasculitis affects your sinuses, nose, throat, and ears, you may have sinus or chronic (ongoing) middle ear infections. Other symptoms include ulcers in the nose and, in some cases, hearing loss.

Eyes

If vasculitis affects your eyes, you may develop red, itchy, burning eyes. Your eyes also may become sensitive to light, and your vision may blur. Rarely, certain types of vasculitis may cause blindness.

Brain

If vasculitis affects your brain, symptoms may include headaches, problems thinking clearly, changes in mental function, or stroke-like symptoms, such as muscle weakness and paralysis (an inability to move).

Nerves

If vasculitis affects your nerves, you may have numbness, tingling, and weakness in various parts of your body. You also may have a loss of feeling or strength in your hands and feet and shooting pains in your arms and legs.

How Is Vasculitis Diagnosed?

Your doctor will diagnose vasculitis based on your signs and symptoms, your medical history, a physical exam, and test results.

Specialists Involved

Depending on the type of vasculitis you have and the organs affected, your doctor may refer you to various specialists, including:

• A rheumatologist (joint and muscle specialist)
• An infectious disease specialist
• A dermatologist (skin specialist)
• A pulmonologist (lung specialist)
• A nephrologist (kidney specialist)
• A neurologist (nervous system specialist)
• A cardiologist (heart specialist)
• An ophthalmologist (eye specialist)
• A urologist (urinary tract and urogenital system specialist)

Diagnostic Tests and Procedures

Many tests are used to diagnose vasculitis.

Blood Tests

Blood tests can show whether you have abnormal levels of certain blood cells and antibodies (proteins) in your blood. These tests may look at:

• Hemoglobin and hematocrit. A low hemoglobin or hematocrit level suggests anemia, a complication of vasculitis. Vasculitis can interfere with the body's ability to make enough red blood cells. Vasculitis also can be linked to increased destruction of red blood cells.
• Antineutrophil cytoplasmic antibodies (ANCA). These antibodies are present in people who have certain types of vasculitis.
• Erythrocyte sedimentation rate (ESR). A high ESR may be a sign of inflammation in the body.
• The amount of C-reactive protein (CRP) in your blood. A high CRP level suggests inflammation.

Biopsy

A biopsy often is the best way for your doctor to make a firm diagnosis of vasculitis. During a biopsy, your doctor will take a small sample of your body tissue to study under a microscope. He or she will take the tissue sample from a blood vessel or an organ.

A pathologist will study the sample for signs of inflammation or tissue damage. A pathologist is a doctor who specializes in identifying diseases by studying cells and tissues under a microscope.

Blood Pressure

People who have vasculitis should have their blood pressure checked routinely. Vasculitis that damages the kidneys can cause high blood pressure.

Urinalysis

For this test, you'll provide a urine sample for analysis. This test detects abnormal levels of protein or blood cells in the urine. Abnormal levels of these substances can be a sign of vasculitis affecting the kidneys.

EKG (Electrocardiogram)

An EKG is a simple, painless test that records the heart's electrical activity. You might have this test to show whether vasculitis is affecting your heart.

Echocardiography

Echocardiography is a painless test that uses sound waves to create a moving picture of your heart. The test gives information about the size and shape of your heart and how well your heart chambers and valves are working.

Chest X Ray

A chest x ray is a painless test that creates pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. Abnormal chest x-ray results may show whether vasculitis is affecting your lungs or your large arteries (such as the aorta or the pulmonary arteries).

Lung Function Tests

Lung function tests measure how much air you can breathe in and out, how fast you can breathe air out, and how well your lungs deliver oxygen to your blood.

Lung function tests can help your doctor find out whether airflow into and out of your lungs is restricted or blocked.

Abdominal Ultrasound

An abdominal ultrasound uses sound waves to create a picture of the organs and structures in your abdomen. The picture may show whether vasculitis is affecting your abdominal organs.

Computed Tomography Scan

A computed tomography (to-MOG-rah-fee) scan, or CT scan, is a type of x ray that creates more detailed pictures of your internal organs than a standard x ray. The results from this test can show whether you have a type of vasculitis that affects your abdominal organs or blood vessels.

Magnetic Resonance Imaging

A magnetic resonance imaging (MRI) test uses radio waves, magnets, and a computer to create detailed pictures of your internal organs.

Angiography

Angiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show blood flowing through your blood vessels.

The dye is injected into your bloodstream. Special x-ray pictures are taken while the dye flows through your blood vessels. The dye helps highlight the vessels on the x-ray pictures.

Doctors use angiography to help find out whether blood vessels are narrowed, swollen, deformed, or blocked.

How Is Vasculitis Treated?

Treatment for vasculitis will depend on the type of vasculitis you have, which organs are affected, and the severity of the condition.

People who have severe vasculitis are treated with prescription medicines. Rarely, surgery may be done. People who have mild vasculitis may find relief with over-the-counter pain medicines, such as acetaminophen, aspirin, ibuprofen, or naproxen.

The main goal of treating vasculitis is to reduce inflammation in the affected blood vessels. This usually is done by reducing or stopping the immune response that caused the inflammation.

Types of Treatment

Common prescription medicines used to treat vasculitis include corticosteroids and cytotoxic medicines.

Corticosteroids help reduce inflammation in your blood vessels. Examples of corticosteroids are prednisone, prednisolone, and methylprednisolone.

Doctors may prescribe cytotoxic medicines if vasculitis is severe or if corticosteroids don't work well. Cytotoxic medicines kill the cells that are causing the inflammation. Examples of these medicines are azathioprine, methotrexate, and cyclophosphamide.

Your doctor may prescribe both corticosteroids and cytotoxic medicines.

Other treatments may be used for certain types of vasculitis. For example, the standard treatment for Kawasaki disease is high-dose aspirin and immune globulin. Immune globulin is a medicine that’s injected into a vein.

Certain types of vasculitis may require surgery to remove aneurysms that have formed as a result of the condition. (An aneurysm is an abnormal bulge in the wall of a blood vessel.)

How Can Vasculitis Be Prevented?

You can't prevent vasculitis. However, treatment can help prevent or delay the complications of vasculitis.

People who have severe vasculitis are treated with prescription medicines. Rarely, surgery may be done. People who have mild vasculitis may find relief with over-the-counter pain medicines, such as acetaminophen, aspirin, ibuprofen, or naproxen.

For more information about vasculitis treatments, go to "How Is Vasculitis Treated?"

Living With Vasculitis

The outcome of vasculitis is hard to predict. It will depend on the type of vasculitis you have, which organs are affected, and the severity of the condition.

If vasculitis is diagnosed early and responds well to treatment, it may go away or go into remission. "Remission" means the condition isn't active, but it can come back, or "flare," at any time.

Flares can be hard to predict. You may have a flare when you stop treatment or change your treatment. Some types of vasculitis seem to flare more often than others. Also, some people have flares more often than others.

Sometimes vasculitis is chronic (ongoing) and never goes into remission. Long-term treatment with medicines often can control chronic vasculitis, but no cure has been found. Rarely, vasculitis doesn't respond well to treatment. This can lead to disability or even death.

Ongoing Care

The medicines used to treat vasculitis can have side effects. For example, long-term use of corticosteroids may lead to weight gain, diabetes, weakness, a decrease in muscle size, and osteoporosis (a bone-thinning condition). Long-term use of these medicines also may increase your risk of infection.

Your doctor may adjust the type or dose of medicine you take to lessen or prevent the side effects. If your vasculitis goes into remission, your doctor may carefully withdraw your medicines. However, he or she will still need to carefully watch you for flares.

While you're being treated for vasculitis, you'll need to see your doctor regularly. Talk with your doctor about any new symptoms and other changes in your health, including side effects of your medicines.

Emotional Issues and Support

Living with a chronic condition may cause fear, anxiety, depression, and stress. Talk about how you feel with your health care team. Talking to a professional counselor also can help. If you’re very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.

Joining a patient support group may help you adjust to living with vasculitis. You can see how other people who have the same symptoms have coped with them. Talk with your doctor about local support groups or check with an area medical center.

Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Clinical Trials

The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.

NHLBI-supported research has led to many advances in medical knowledge and care. Often, these advances depend on the willingness of volunteers to take part in clinical trials.

Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions. For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.

By taking part in a clinical trial, you can gain access to new treatments before they’re widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don’t directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.

If you volunteer for a clinical trial, the research will be explained to you in detail. You’ll learn about treatments and tests you may receive, and the benefits and risks they may pose. You’ll also be given a chance to ask questions about the research. This process is called informed consent.

If you agree to take part in the trial, you’ll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.

For more information about clinical trials related to vasculitis, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:

• http://clinicalresearch.nih.gov
• www.clinicaltrials.gov
• www.nhlbi.nih.gov/studies/index.htm
• www.researchmatch.org

For more information about clinical trials for children, visit the NHLBI’s Children and Clinical Studies Web page.

Links to Other Information About Vasculitis

NHLBI Resources

• Aneurysm (Health Topics)
• Kawasaki Disease (Health Topics)

Non-NHLBI Resources

• Behçet's Disease (National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS))
• Buerger’s Disease (MedlinePlus)
• Cryoglobulinemia (MedlinePlus)
• Henoch-Schönlein Purpura (National Institute of Diabetes and Digestive and Kidney Diseases)
• Henoch-Schönlein Purpura (MedlinePlus)
• Hypersensitivity Vasculitis (Allergic Vasculitis) (MedlinePlus)
• Kawasaki Disease (MedlinePlus)
• Polyarteritis Nodosa (MedlinePlus)
• Polymyalgia Rheumatica and Giant Cell Arteritis (NIAMS)
• Takayasu’s Arteritis (MedlinePlus)
• Vasculitis (MedlinePlus)
• Vasculitis (MedlinePlus Interactive Tutorial)
• Wegener's Granulomatosis (National Institute of Allergy and Infectious Diseases)

Clinical Trials

• Children and Clinical Studies
• Clinical Trials (Health Topics)
• Current Research (ClinicalTrials.gov)
• NHLBI Clinical Trials
• NIH Clinical Research Trials and You (National Institutes of Health)
• ResearchMatch (funded by the National Institutes of Health)