What is Churg-Strauss syndrome?
Churg-Strauss syndrome (CSS) is an extremely rare disease that results from inflammation and which causes injury to organ systems. The areas most commonly affected by CSS include the nerves, sinuses, skin, joints, lungs, intestinal tract, heart, and kidneys. Almost all people with CSS will have a history of asthma and/or nasal allergies.
The inflammation that is seen in CSS can be of several types. Almost all people with CSS have increased numbers of “allergic type” blood cells called eosinophils. Eosinophils can be found in elevated numbers in the blood and often in tissue biopsies in people with CSS. Another type of inflammation called granulomatous inflammation can also occur in CSS. Some of the most serious manifestations of CSS are related to the presence of vasculitis.
What is vasculitis?
Vasculitis is a general term that refers to inflammation of the blood vessels. When blood vessels become inflamed, they can only react in limited ways. When inflamed, the blood vessel may become weakened and stretch in size, which can lead to aneurysms, or become so thin that they rupture resulting in bleeding into the tissue. Vasculitis can also cause blood vessel narrowing to the point of closing off the vessel entirely. This can cause organs to become damaged from loss of oxygen and nutrients that were being supplied by the blood.
What are the symptoms of CSS?
Because many different organ systems may be involved, a wide range of symptoms are possible in CSS.
Patients who have CSS may feel generally ill and fatigued, have fevers, or have loss of appetite and weight. They usually also have symptoms related to areas of involvement, such as shortness of breath or chest pain from disease affecting the lungs or heart, rashes, muscle and/or joint pain, increased nasal discharge or facial pain from sinusitis, and abdominal pain or blood in the stools occurring as a result of intestinal tract involvement. CSS affecting the nerves may cause an abnormal sensation followed by numbness or loss of strength. Any combination of these symptoms may be present.
Kidney disease caused by CSS often does not produce symptoms. Inflammation of the kidney may not be apparent to the patient until the kidneys begin to stop working. Therefore, it is very important for the physician, in dealing with any form of vasculitis, to always examine the urine.
What causes CSS?
The cause of CSS is unknown. CSS is not a form of cancer, it is not contagious, and it does not usually occur within families. Evidence from the research laboratory strongly supports that the immune system plays a critical role in CSS in that the immune system becomes overactive, causing blood vessel and tissue inflammation and damage. What causes the immune system to become overactive is not currently known.
Who is affected by CSS?
CSS can occur in people of all ages, from children to the elderly. The average age of people with CSS at diagnosis is between 35 and 50 years old. CSS appears to affect men and women equally.
How is CSS diagnosed?
Suspicion for CSS is based on information gathered from a variety of sources, including:
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Medical history to look for the presence of CSS symptoms, especially the presence of asthma and other features suggestive of disease.
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Physical examination to detect sites of organ involvement and to exclude other illnesses that may have a similar appearance.
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Blood tests to look for abnormal blood counts with an increase in eosinophils.
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Urinalysis to detect excessive protein or the presence of red blood cells.
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Imaging tests such as x-rays, computed tomography (CT) or magnetic resonance (MR) scans, which can show abnormalities in areas such as the lungs or sinuses.
Once the diagnosis of CSS is suspected, a biopsy (tissue sample) of an affected area is often performed to try to confirm the presence of vasculitis. Biopsies are only recommended for organ sites in which there are abnormal findings present by examination, laboratory tests, or imaging.
How is CSS treated?
Medications that suppress the immune system form the foundation of treatment for CSS. There are a variety of immunosuppressive medications that are used in CSS, each of which have individual side effects. The choice of which medication to use is based upon individual patient factors, the most important of which is the severity of the CSS. Disease severity can vary widely in CSS, ranging from milder manifestations -- such as those affecting the skin or joint -- to those that can be potentially life threatening.
Corticosteroid, such as prednisone or prednisolone, are the most commonly used medications in the treatment of CSS. People who do not have manifestations affecting the nervous system, heart, kidneys, intestinal tract or other features of severe disease might do extremely well with corticosteroid therapy alone.
People with CSS who have critical organ system involvement are generally treated with corticosteroids combined with another immunosuppressive medication such as cyclophosphamide (Cytoxan), methotrexate, or azathioprine (Imuran). All of these medications are also used to treat other medical conditions. Azathioprine is used to prevent organ transplant rejection and has been applied to the treatment of rheumatoid arthritis and systemic lupus erythematosus. Both cyclophosphamide and methotrexate are given at high doses as a treatment for certain types of cancer and therefore are sometimes referred to as “chemotherapy.” In cancer treatment, these medications work by killing or slowing the growth of rapidly multiplying cancer cells. In vasculitis, these medications are given at doses that are 10 to 100 times lower than those used to treat cancer, and their primary effect is to influence the behavior of the immune system in a manner that results in immunosuppression.
All immunosuppressive medications can have side effects. Monitoring for side effects plays a critical role in preventing or minimizing their occurrence. Each medication has a unique side effect profile that forms the basis for the monitoring plan. The fact that someone with CSS may initially tolerate treatment does not guarantee that the person will have the same degree of tolerance over time. This makes ongoing monitoring essential, and in some instances, monitoring for long-term effects may be important even after the medication is stopped.
The goal of treatment is to stop all damage that is occurring as a result of CSS -- this is often referred to as “remission.” Once it is apparent that the disease is improving, doctors slowly reduce the corticosteroid dose and eventually hope to discontinue it completely. Complete discontinuation may be particularly difficult if a person has significant asthma, as the airways can be very sensitive to corticosteroids. If cyclophosphamide is used for severe CSS, it is often only given until the time of remission (usually around 3 to 6 months), after which time the patient is switched to another immunosuppressive agent, such as methotrexate or azathioprine to maintain remission. The treatment duration of maintenance immunosuppressive medication may vary between individuals. In most instances, it is given for a minimum of one to two years before consideration is given to the possibility of slowly reducing the dosage to discontinuation.
What is the outlook for patients with CSS?
Because CSS is a rare disease, accurate statistics on overall outcome are only approximate. On average, after 5 years of illness, over 80 percent of people have survived the effects of CSS. How people with CSS do is strongly related to the severity of their illness. Although CSS can be a progressive and serious illness, many people with CSS do extremely well.
The best opportunity for minimal organ damage to occur comes when treatment has been promptly initiated and is carefully monitored by a physician who is knowledgeable about CSS. Even patients who have the most severe CSS can achieve remission when treated promptly and followed closely.
After achieving remission, it is possible for the CSS to recur (often referred to as a “relapse”). People with asthma or nasal allergies can frequently experience worsening of these symptoms that is independent of vasculitis. Relapses involving vasculitis occur in about 30 percent to 50 percent of people with CSS. Such relapses may be similar to what the person experienced at the time of their diagnosis or they may be different. The likelihood of experiencing a severe relapse can be minimized by prompt reporting to the physician of any new symptoms, regular physician follow-up, and ongoing monitoring with laboratory tests and imaging. The treatment approach for relapses is similar to that of newly diagnosed disease with achievement of remission again being possible for most people with CSS.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 10/30/2006
