Churg-Strauss Syndrome

What is Churg-Strauss syndrome?

Churg-Strauss syndrome is a rare disease that causes inflammation in the small and medium arteries in the body. Churg-Strauss is now known as eosinophilic granulomatosis with polyangiitis (EGPA).

Immune system cells, called eosinophils, that are normally involved in the body’s allergic response, start to multiply, causing damage. It can affect most organs in the body. Most commonly, it causes asthma, sinus inflammation, or a rash. But it can lead to a range of other symptoms.

EGPA is treated with medicine that suppresses the immune system. People may need treatment for 1 to 2 years, and some may need it for the rest of their life. Without treatment, it can lead to life-threatening complications.

Most common symptoms

EGPA can have many different symptoms. There are three main phases of the disease, but not everyone experiences clear phases. When someone has clear phases, they often happen in this order:

Prodromal phase is the earliest. People have asthma, seasonal allergies or hay fever, and other issues related to allergies. It’s difficult to diagnose EGPA in this phase since these symptoms (like asthma) are so common. Most people with asthma will not have EGPA.

Eosinophilic phase is when there is an increase in eosinophils, a type of white blood cell that helps with the allergic response. These cells may invade organs, especially the lungs and digestive tract. This can cause symptoms such as shortness of breath, cough, stomach pain, and diarrhea.

The timeline of the phases varies, but asthma often appears 8 to 10 years before the next phase (vasculitic phase).

Vasculitic phase is marked by inflammation of blood vessels (vasculitis). Chronic vasculitis may cause narrowing of blood vessels, blocking or slowing the flow of blood to your organs.

People in this phase may have fever, weight loss, and fatigue. There are other symptoms depending on which organs are affected. They include red/purple raised skin bumps or pain, numbness, and or weakness in a specific area of the body.

Causes of EGPA

For reasons that are not clear, the immune system behaves abnormally. There are two main issues. The first is that your body starts producing a lot of eosinophils, which then invade parts of the body.

Second, your body makes antibodies, which causes the immune system to attack healthy cells. In later stages of the disease, your blood vessels may become inflamed.

It’s not known what prompts this immune response. Certain genetic differences may raise your risk of EGPA. Most people with EGPA have asthma for 5 to 10 years before they reach the most advanced phase of the disease. But the vast majority of people with asthma never develop EGPA.

Next steps

Most people with EGPA have what seems like normal asthma for many years before developing EGPA. If you have asthma and develop other symptoms listed above (including uncontrolled asthma despite medications, chronic sinus problems, rashes), talk to your primary care doctor.

They may choose to run some blood tests. If they’re concerned about EGPA, you’ll be sent to a specialist, like a rheumatologist (or a pulmonologist, if your lungs are involved).

Treating EGPA

Treatment is necessary to slow the progression of the disease and may be able to reverse damage done to organs. People with severe EGPA disease are often treated with a powerful medicine that suppresses the immune system. Depending on which medication a doctor chooses, treatment may continue for 1 to 2 years.

Once the immune system has been tamped down, long-term maintenance therapy is often used. This helps keep the immune system from becoming over-active again.

Medication

• Steroids (e.g., prednisone, methylprednisolone) are often used in high doses to suppress the immune response. They can also be taken in lower doses long term. But steroids have a number of side effects, so your doctor will avoid using them long term as much as possible.
• Cyclophosphamide is an intravenous (IV) infusion. Sometimes, doctors use this in addition to steroids for people with severe EGPA. It is not given long term.
• Azathioprine is used after EGPA goes into remission to help maintain remission. It is used after treatment with steroids or cyclophosphamide. It is often the long-term medication that doctors prefer.
• Methotrexate can be used instead of azathioprine to help suppress the immune system long term after treatment with steroids or cyclophosphamide. However, methotrexate can cause side effects in your lungs. That can make it hard to know whether you are having worse EGPA symptoms or side effects from the medication itself.
• Leflunomide is sometimes used after remission as maintenance therapy.
• Mepolizumab is used to help treat severe asthma. It also helps lower the amount of steroids you need.
• Inhaled steroids are commonly used to treat asthma. They can also help asthma symptoms in people with EGPA.

Follow up

EGPA is a chronic disease that can cause severe health problems if it isn’t treated. If you have EGPA, it is important to follow up regularly with your specialist.