Churg-Strauss is a highly variable illness. Some people have only mild symptoms, whereas others experience severe or life-threatening complications. There are three stages of Churg-Strauss syndrome, each with its own signs and symptoms, but not everyone develops all three phases or in the same order. This is especially true when the disease is caught and treated before the most serious damage occurs.

Churg-Strauss stages may include:

Allergic
This is usually the first stage of Churg-Strauss syndrome. It's marked by a number of allergic reactions, including:

• Asthma. The primary sign of Churg-Strauss syndrome, asthma may develop as long as a decade before other signs and symptoms appear or the disease is diagnosed. In people with Churg-Strauss syndrome who already have asthma, symptoms usually become worse and may require steroids for control. Other people develop what is known as late-onset asthma. Developing asthma, even later in life, doesn't necessarily mean that you have Churg-Strauss syndrome, however.
• Hay fever (allergic rhinitis). This affects the mucous membranes of your nose, causing runny nose, sneezing and itching.
• Sinus pain and inflammation (sinusitis). You may experience facial pain and develop nasal polyps, which are soft, noncancerous (benign) growths that develop as a result of chronic inflammation.

Hypereosinophilia
An eosinophil is a type of white blood cell that helps your immune system fight certain infections. Normally, eosinophils make up only a small percentage of white blood cells, but in Churg-Strauss syndrome, abnormally high numbers of these cells are found in your blood or tissues, where they can cause serious damage.

Signs and symptoms of hypereosinophilia depend on which part of your body is affected. Your lungs and digestive tract — including your stomach and esophagus — are involved most often.

Broadly speaking, signs and symptoms of the hypereosinophilia phase may include:

• Fever
• Weight loss
• Fatigue
• Night sweats
• Cough
• Abdominal pain
• Gastrointestinal bleeding

This phase can last months or years, and your symptoms may disappear at times, only to return later. You also may experience symptoms of hypereosinophilia and systemic vasculitis — the third stage of Churg-Strauss syndrome — at the same time.

Systemic vasculitis
The hallmark of this stage of Churg-Strauss syndrome is severe blood vessel inflammation (vasculitis). By narrowing blood vessels, inflammation reduces blood flow to vital organs and tissues throughout your body, including your skin, heart, peripheral nervous system, muscles, bones and digestive tract. Occasionally, your kidneys may also be affected.

During this phase, you may feel generally unwell and have unintended weight loss, swollen lymph nodes, weakness and fatigue.

Depending on which organs are affected, you may also experience:

• Rash or skin sores
• Joint aches and swelling
• Severe pain, numbness and tingling in your hands and feet (peripheral neuropathy)
• Severe abdominal pain
• Diarrhea, nausea and vomiting
• Shortness of breath (dyspnea)
• Coughing up blood (hemoptysis)
• Chest pain
• Irregular heartbeat
• Blood in your urine (hematuria)

When to see a doctor
See your doctor anytime you develop breathing difficulties or a runny nose that doesn't go away, especially if it's accompanied by persistent facial pain. Also see your doctor if you have asthma or hay fever that suddenly worsens. Churg-Strauss syndrome is rare, and it's more likely that these symptoms have some other cause, but it's important that your doctor evaluate them.

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The cause of Churg-Strauss syndrome is probably a combination of factors, although those factors haven't yet been identified. It is known that people with Churg-Strauss syndrome have an overzealous immune system. Instead of simply protecting against invading organisms such as bacteria and viruses, the immune system targets healthy tissue, causing widespread inflammation. Researchers are still trying to learn what triggers this inappropriate immune response.

The role of medications
Some people have developed Churg-Strauss syndrome after using an asthma and allergy medication called montelukast or when switching from low-dose systemic steroids to inhaled steroid medications. Studies have not shown a clear link between these medications and Churg-Strauss syndrome, however, and whether a connection exists remains a point of controversy among experts.

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It's not known precisely how many people have Churg-Strauss syndrome, but the disease is rare, affecting somewhere between 700 and 3,000 people in the United States. Given this, it's clear that although many people may have risk factors for the disease, very few actually develop it.

Risk factors for Churg-Strauss syndrome include:

• Age. The average age of people diagnosed with Churg-Strauss syndrome is 50, but people as young as their 30s can have signs and symptoms of systemic vasculitis. The disorder is rare in older adults and children.
• History of asthma or nasal problems. Most people diagnosed with Churg-Strauss syndrome have a history of nasal allergies, chronic sinusitis or asthma, which is often severe or hard to control.

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Churg-Strauss can affect many organs, including your lungs, skin, gastrointestinal system, kidneys, muscles, joints and heart. Without treatment, the disease may be fatal. Complications depend on the organs involved and may include:

• Peripheral nerve damage. Peripheral nerves extend throughout your body, connecting your organs, glands, muscles and skin with your brain and spinal cord. Churg-Strauss syndrome can damage peripheral nerves (peripheral neuropathy), especially those in your hands and feet, leading to numbness, burning and loss of function. In some people, this damage may be permanent.
• Skin scarring. The inflammation may cause sores to develop that can leave scars.
• Heart disease. Heart-related complications of Churg-Strauss syndrome include inflammation of the membrane surrounding your heart (pericarditis), inflammation of the muscular layer of your heart wall (myocarditis), heart attack and heart failure.
• Kidney (renal) damage. If Churg-Strauss syndrome affects your kidneys, you may develop glomerulonephritis, a type of kidney disease that hampers your kidneys' filtering ability, leading to a buildup of waste products in your bloodstream (uremia). Although kidney failure isn't common with this disease, it can be fatal when it occurs.

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Churg-Strauss syndrome is challenging to diagnose. Providing your doctor with as much information as possible can help the diagnostic process. These suggestions may help you prepare for your appointment:

• Write down all your symptoms and how long they've been present — even those that seem unrelated to your main problem. Churg-Strauss syndrome can cause symptoms throughout your body and not always in a classic order. It's important that your doctor know exactly what you experienced and when.
• Write down questions that you want to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something your doctor says. Start with the problems that concern you most. If you run out of time, ask to speak with a nurse or physician's assistant or leave a message for your doctor.
• Bring someone with you — a friend, family member or trusted colleague. Churg-Strauss is a complicated disorder, and it can be helpful to have another person who can help remember something that you forgot or missed.

If your primary care physician suspects Churg-Strauss syndrome, you will likely be referred to a doctor who specializes in disorders that cause blood vessel inflammation (vasculitis), such as a rheumatologist or immunologist.

At the time you make this appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet. Also ask if you need to stay at your doctor's office for observation following your tests.

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There are no specific tests to confirm Churg-Strauss syndrome, and signs and symptoms are similar to those of other diseases, so it can be difficult to diagnose. To help make diagnosis easier, the American College of Rheumatology has established criteria for identifying Churg-Strauss syndrome.

The six criteria
The disease is generally considered to be present if a person has four of the six criteria, but your doctor may feel confident diagnosing Churg-Strauss even if you meet only two or three of the criteria, which include:

• Asthma
• Eosinophilia — eosinophils normally make up 1 to 3 percent of white blood cells; a count higher than 10 percent is considered abnormally high and a strong indicator of Churg-Strauss syndrome
• Mononeuropathy or polyneuropathy — damage to one or more nerve groups
• Pulmonary infiltrates — spots or lesions on a chest X-ray that move from one place to another or come and go
• History of acute or chronic sinus pain
• Extravascular eosinophils — white cells that are present outside your blood vessels

To help determine whether you meet any of these criteria, your doctor is likely to request several tests, including:

• Blood tests. When your immune system attacks your body's own cells, as happens in Churg-Strauss syndrome, it forms proteins called autoantibodies. A blood test can detect certain autoantibodies in your blood that can suggest, but not confirm, a diagnosis of Churg-Strauss syndrome. A blood test also can measure the level of eosinophils, although an increased number of these cells may be caused by other diseases, including asthma.
• Imaging tests. X-rays, computerized tomography (CT) scans and magnetic resonance imaging (MRI) look for abnormalities in your lungs and sinuses.
• Biopsy of affected tissue. If other tests suggest Churg-Strauss syndrome, you may have a small sample of tissue (biopsy) removed for examination under a microscope. The doctor may remove tissue from your lungs or another organ, such as skin or muscle, to confirm or rule out the presence of vasculitis. A biopsy is usually performed only on a site that has shown some abnormality on another test.

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There's no cure for Churg-Strauss syndrome, but certain medications may help even people with serious symptoms achieve remission. A good outcome and a reduced risk of complications from both the disease and its treatment are more likely when Churg-Strauss syndrome is diagnosed and treated early.

Medications used to treat Churg-Strauss syndrome include:

• Corticosteroids. Prednisone is the most commonly prescribed drug for Churg-Strauss syndrome. Your doctor may prescribe a high dose — 40 to 60 milligrams a day — of corticosteroids to get your symptoms under control as soon as possible. But because high doses of corticosteroids can cause serious side effects, including bone loss, high blood sugar, cataracts and hard-to-treat infections, your doctor will decrease the dose gradually until you're taking the smallest amount that will keep your disease under control. Even lower doses taken for extended periods can cause side effects, however.
• Other immunosuppressive drugs. For people with mild symptoms, a corticosteroid alone may be enough. Other people may require another immunosuppressive drug, such as cyclophosphamide (Cytoxan), azathioprine (Imuran) or methotrexate (Rheumatrex, Trexall), to reduce the body's immune reaction still further. Because these drugs impair your body's ability to fight off infection and can cause other serious side effects, your doctor must closely monitor your condition while you're taking them.
• Intravenous immunoglobulin (IVIg). Given as a monthly infusion, IVIg is the most benign of the treatments used for Churg-Strauss syndrome. The most common side effects are flu-like symptoms that usually last just a day or so. IVIg has two major drawbacks, however: It's very expensive, and it isn't universally effective. IVIg isn't considered a first line treatment for Churg-Strauss, but studies have shown that it can be helpful for people who don't respond to other medications.

Although drug therapy can quell symptoms of Churg-Strauss syndrome — and send the disease into remission — relapses are common.

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Long-term treatment with prednisone can cause a number of side effects, but you can take steps to help minimize them.

• Protect your bones. If you're taking cortisone, it's essential to get adequate amounts of calcium to prevent bone loss and possible fractures. Getting enough vitamin D is just as important. Not only does vitamin D improve bone health by helping calcium absorption, but it also may improve muscle strength. Scientists are continuing to study vitamin D — which may protect against certain types of cancer — to determine the optimal daily dose, but it's safe to take up to 2,000 international units (IU) a day. Strength-training and weight-bearing exercises such as walking and jogging also are essential for bone health.
• Exercise. In addition to keeping your bones strong, exercise can help you maintain a healthy weight. This is significant because cortisone tends to cause weight gain, which in turn can contribute to diabetes — another side effect of cortisone therapy. Regular exercise is also important for people dealing with the pain of neuropathy.
• Stop smoking. This is one of the most significant things you can do for your overall health. By itself, smoking causes serious health problems. It also makes problems you already have worse and can exacerbate medication side effects.
• Adopt a healthy diet. Steroids can cause high blood sugar levels and eventually, fullblown diabetes. Emphasizing foods that help keep blood sugar on an even keel, such as fruits, vegetables and whole grains, is key. So is having your glucose and A1C levels checked regularly.
• Keep doctor appointments. During therapy for Churg-Strauss syndrome, your doctor will monitor you closely for side effects. This will likely include regular bone scans, eye exams, and blood pressure, glucose and cholesterol checks. Be sure to keep these appointments. If caught in time, it's possible to reverse many of the side effects associated with steroid use.

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Churg-Strauss is a serious and sometimes devastating disease. Even when it's in remission, you may worry about the possibility of recurrence or about long-term damage to your heart, lungs and nerves. Here are some suggestions for coping with the disease:

• Educate yourself about Churg-Strauss syndrome. The more you know, the better prepared you'll be to deal with complications or recurrences. Besides talking to your doctor, you may want to talk to a counselor or medical social worker. Or you may find it helpful to talk to other people with Churg-Strauss syndrome.
• Maintain a strong support system. Although family and friends can help tremendously, you sometimes may find the understanding and in-the-trenches advice of other people with Churg-Strauss syndrome especially helpful. Your doctor or a medical social worker may be able to put you in touch with a support group. Or you can look for a real or virtual support group through the Churg-Strauss Syndrome Association.

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