Eosinophilic Granulomatosis with Polyangiitis
(Churg-Strauss Syndrome; Allergic Granulomatosis and Angiitis)
(See also Overview of Vasculitis.)
Eosinophilic granulomatosis with polyangiitis (formerly called Churg-Strauss syndrome) is inflammation of small- and medium-sized blood vessels that damages organs and that usually occurs in adults with a history of asthma, nasal allergies, nasal polyposis, or a combination.
The cause is unknown.
At first, people may have a runny nose or asthma for months or years or have sinus pain, followed by various symptoms, depending on which organs are affected.
Doctors base the diagnosis on symptoms and results of a physical examination, blood tests, a chest x-ray, and biopsy.
Corticosteroids are usually effective, but if a vital organ is affected, another drug that suppresses the immune system may be used.
Eosinophilic granulomatosis with polyangiitis can occur in people of all ages. The average age at the time of diagnosis is 48. Affected people develop asthma, nasal allergies, nasal polyposis (when numerous polyps develop in the nose), or a combination in adulthood. The cause is unknown.
Inflammation that can affect small- and medium-sized blood vessels (vasculitis) may affect any organ. The peripheral nervous system, sinuses, skin, joints, lungs, digestive tract, heart, and kidneys are most commonly affected. Collections of immune cells that cause inflammation (called granulomas) may form raised bumps (nodules) in affected tissue. Granulomas can destroy normal tissue and interfere with functioning. They may also cause lumps to form under the skin. People also have an increased number of eosinophils (a type of white blood cell) in their blood and body tissues. An increased number of eosinophils is called eosinophilia, and the increase suggests that an allergic reaction may be part of the disorder.
At first, asthma, nasal allergies, nasal polyposis, or a combination may develop or worsen over many years. People may sneeze and have a persistently runny nose and itchy eyes. Inflammation of the sinuses may cause facial pain.
Later, people may feel generally ill and tired. They may have fevers or night sweats or lose their appetite and lose weight. Other symptoms depend on which organs are affected and may include the following:
Any combination of these symptoms may occur. Symptoms may occur in episodes. In subsequent episodes, people may have the same symptoms as the first episode or different ones.
Inflammation of the kidneys may not cause symptoms until the kidneys malfunction and kidney failure develops. Other complications include heart failure, heart attacks, pericarditis, and heart valve disorders.
Early diagnosis and treatment help prevent severe organ damage.
No single test can confirm the diagnosis. The diagnosis is made by recognizing the combination of typical symptoms and results of the physical examination and other tests.
Blood tests are done. Doctors determine how many eosinophils are in the blood. Eosinophils are produced during allergic reactions, and their number increases when eosinophilic granulomatosis with polyangiitis is present. Doctors also look for certain antibodies (antineutrophil cytoplasmic antibodies) that may be present. Doctors measure how quickly red blood cells (erythrocytes) drop to the bottom of a test tube (erythrocyte sedimentation rate, or ESR). A fast rate suggests inflammation. Doctors also measure levels of C-reactive protein (which the liver produces in response to bodywide inflammation). A high C-reactive protein level also suggests inflammation. A chest x-ray is done to look for inflammation in the lungs. Urine tests are done to determine whether the kidneys are affected.
A sample of inflamed tissue is taken and examined under a microscope (biopsy). A biopsy can show whether the tissue contains eosinophils or granulomas. If possible, a sample is taken from the skin or muscle because the biopsy can then be done as an outpatient procedure with only a local anesthetic. Sometimes a biopsy of lung tissue is necessary. It may require hospitalization.
Corticosteroids (such as prednisone) are given. These drugs can reduce inflammation. If a vital organ is affected, another drug that suppresses the immune system (immunosuppressant) is also used. Azathioprine or methotrexate may be used. Cyclophosphamide is used when the symptoms are severe.
After symptoms resolve, the dose of the drugs is gradually reduced, and, after a while, the drugs may be stopped. If necessary, they can be started again. These drugs, especially when taken for a long time, can have serious side effects.
People with eosinophilic granulomatosis with polyangiitis should learn about their disorder. Then they can recognize any new symptoms and report them immediately to the doctor.
The prognosis is poor for people whose kidneys, heart, brain, spinal cord, or nerves are affected.