Churg-Strauss syndrome varies greatly from person to person. Some people have only mild symptoms. Others have severe or life-threatening complications.

Also known as EGPA, the syndrome tends to occur in three stages and gets progressively worse. Almost everyone with the condition has asthma, chronic sinusitis and elevated counts of white blood cells called eosinophils.

Other signs and symptoms might include:

• Loss of appetite and weight loss
• Joint and muscle pain
• Abdominal pain and gastrointestinal bleeding
• Weakness, fatigue or a general feeling of being unwell
• Rash or skin sores
• Pain, numbness, and tingling in your hands and feet

See your doctor if 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 nasal allergies that suddenly worsen.

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. Early diagnosis and treatment improve the chances of a good outcome.

The cause of Churg-Strauss syndrome is largely unknown. It's likely that a combination of genes and environmental factors, such as allergens or certain medications, triggers an overactive immune system response. Instead of protecting against invading bacteria and viruses, the immune system targets healthy tissue, causing widespread inflammation.

While anyone can get Churg-Strauss syndrome, people are usually around age 50 when diagnosed. Other potential risk factors include chronic asthma or nasal problems. Genetics and exposures to environmental allergens also may play a role.

Churg-Strauss syndrome can affect many organs, including the lungs, sinuses, skin, gastrointestinal system, kidneys, muscles, joints and heart. Without treatment, the disease can be fatal.

Complications, which depend on the organs involved, can include:

• Peripheral nerve damage. Churg-Strauss syndrome can damage the nerves in your hands and feet, leading to numbness, burning and loss of function.
• Heart disease. Heart-related complications of Churg-Strauss syndrome include inflammation of the membrane surrounding your heart, inflammation of the muscular layer of your heart wall, heart attack and heart failure.
• Kidney damage. If Churg-Strauss syndrome affects your kidneys, you can develop glomerulonephritis. This disease hampers your kidneys' filtering ability, leading to a buildup of waste products in your bloodstream.

To diagnose Churg-Strauss syndrome, doctors usually request several types of tests, including:

• Blood tests. A blood test can detect certain antibodies in your blood that can suggest, but not confirm, a diagnosis of Churg-Strauss syndrome. It can also measure the level of eosinophils, although other diseases, including asthma, can increase the number of these cells.
• Imaging tests. X-rays and CT scans can reveal abnormalities in your lungs and sinuses. If you develop signs of heart failure, your doctor may also suggest regular echocardiograms.
• Biopsy of affected tissue. If other tests suggest Churg-Strauss syndrome, you might have a small sample of tissue removed for examination under a microscope. The tissue can come from your lungs or another organ, such as skin or muscle, to confirm or rule out the presence of vasculitis.

There's no cure for Churg-Strauss syndrome, also known as eosinophilic granulomatosis with polyangiitis (EGPA). But medications can help manage your symptoms.

Corticosteroids

Prednisone, which reduces inflammation, is the most commonly prescribed drug for Churg-Strauss syndrome. Your doctor might prescribe a high dose of corticosteroids or a boost in your current dose of corticosteroids to get your symptoms under control quickly.

High doses of corticosteroids can cause serious side effects, so 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.

Side effects of corticosteroids include bone loss, high blood sugar, weight gain, cataracts and hard-to-treat infections.

Other immunosuppressive drugs

For people with mild symptoms, a corticosteroid alone may be enough. Other people may need to add another drug to help suppress their immune systems.

Mepolizumab (Nucala) is currently the only drug approved by the U.S. Food and Drug Administration for treatment of Churg-Strauss syndrome. However, depending on the severity of disease and the organs involved, other medications may be required. Examples include:

• Azathioprine (Azasan, Imuran)
• Benralizumab (Fasenra)
• Cyclophosphamide
• Methotrexate (Trexall)
• Rituximab (Rituxan)

Because these drugs impair your body's ability to fight infection and can cause other serious side effects, your condition will be closely monitored while you're taking them.

Long-term treatment with corticosteroids can cause a number of side effects. You can minimize these problems by taking the following steps:

• Protect your bones. Ask your doctor how much vitamin D and calcium you need in your diet, and discuss whether you should take supplements.
• Exercise. Exercise can help you maintain a healthy weight, which is important when you're taking corticosteroid medications that can cause weight gain. Strength training and weight-bearing exercises such as walking and jogging also help improve bone health.
• Eat a healthy diet. Steroids can cause high blood sugar levels and, eventually, type 2 diabetes. Eat foods that help keep blood sugar stable, such as fruits, vegetables and whole grains.

Here are some suggestions for coping with Churg-Strauss syndrome:

• Educate yourself. Knowing about the disease can help prepare you to deal with complications or recurrences.
• Build a support system. Family and friends can help tremendously. You might also want to talk to a counselor or medical social worker who's familiar with the disease. Or you may find it helpful to talk to other people with Churg-Strauss syndrome.

If you have signs and symptoms common to Churg-Strauss syndrome, make an appointment with your doctor. Early diagnosis and treatment significantly improve the outlook of this condition.

You may be referred to a doctor who specializes in disorders that cause blood vessel inflammation (vasculitis), such as a rheumatologist or immunologist. You might also see a pulmonologist since Churg-Strauss affects your respiratory tract.

Here's some information to help you get ready for your appointment.

What you can do

When you make an appointment, ask if you need to do anything in advance, such as restrict your diet. Also ask if you need to stay at your doctor's office for observation following your tests.

Make a list of:

• Your symptoms and when they began, even those that seem unrelated to Churg-Strauss syndrome
• Key medical information, including other conditions with which you've been diagnosed
• All medications, vitamins and other supplements you take, including doses
• Questions to ask your doctor

If you've seen other doctors for your condition, bring a letter summarizing their findings and copies of recent chest X-rays or sinus X-rays. Take a family member or friend along to help you remember the information you receive.

Basic questions to ask your doctor might include:

• What's the most likely cause of my condition?
• What are other possible causes?
• What diagnostic tests do I need?
• What treatment do you recommend?
• What life changes can I make to help reduce or manage my symptoms?
• How often will you see me for follow-up tests?

What to expect from your doctor

A doctor who sees you for possible Churg-Strauss syndrome is likely to ask you questions, such as:

• Have your symptoms, especially asthma-related, worsened over time?
• Do your symptoms include shortness of breath or wheezing?
• Do your symptoms include sinus problems?
• Do your symptoms include gastrointestinal problems, such as nausea, vomiting or diarrhea?
• Have you been having numbness, pain, or weakness in an arm or leg?
• Have you lost weight without trying?
• Have you been diagnosed with any other medical conditions, including allergies or asthma? If so, how long have you had them?