An Overview of Churg Strauss Syndrome

A rare autoimmune condition that causes inflammation of the blood vessels

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Churg Strauss Syndrome, also known as Eosinophilic granulomatosis with polyangiitis (EGPA), is a rare autoimmune condition that causes inflammation of the blood vessels (vasculitis).

Nurse listening to patient lungs
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Churg Strauss Syndrome primarily affects the lungs but can affect many organ systems. The symptoms depend on which organs are affected, though the majority of patients have asthma or asthma-like symptoms. A key feature of Churg Strauss Syndrome is a high number of white blood cells called eosinophils (hypereosinophilia).

Usually, the body releases eosinophils during allergic reactions and parasitic infections. In patients with Churg Strauss Syndrome, large numbers of the cells are released and accumulate in the body's tissues. A patient's symptoms will correspond to the organ systems where the eosinophils are most concentrated. For example, high numbers of eosinophils in the lungs will produce respiratory symptoms, while a high number of the cells in the intestines will cause gastrointestinal symptoms.

Symptoms of Churg Strauss are grouped into three distinct phases, but patients may not experience the phases in order and don't always experience all three phases. In fact, recognizing the phases of Churg Strauss symptoms is important: if the condition is diagnosed when it's in an earlier phase, treatment can help prevent later phases from developing.

The three phases of Churg Strauss Syndrome are:

  1. The prodromal phase: The first phase may last for many months, years, or even decades. During this phase, a person with Churg Strauss typically develops asthma or asthma-like symptoms.
  2. The eosinophilic phase: The second phase begins when the body releases high numbers of eosinophils which begin to accumulate in the body's tissues. The cells can build up in the lungs, intestines, and/or skin. A patient will develop symptoms that correspond with the organ system the cells are accumulating in.
  3. The vasculitic phase: The third phase occurs when the build-up of eosinophils causes widespread inflammation in the blood vessels, a condition called vasculitis. In addition to causing symptoms of pain and bleeding, prolonged, chronic inflammation of the blood vessels can weaken them and put patients at risk for potentially fatal complications such as aneurysms.

Symptoms of Churg Strauss can vary widely, as can when they begin and how long they last. The first symptoms (which occur during the prodromal phase) are usually respiratory. These initial symptoms can include:

  • Itchy, runny nose
  • Sinus pressure and pain
  • Nasal polyps
  • Coughing or wheezing

In the second phase, symptoms can be more generalized and include:

  • Fatigue
  • Night sweats
  • Abdominal pain
  • Fever

During the third phase, the inflammatory symptoms of vasculitis appear and can include:

  • Joint pain
  • Weight loss
  • Rashes
  • Numbness or tingling
  • Muscle pain

More serious symptoms can develop if particular organs, such as the heart and kidneys, are involved. Approximately 78 percent of patients with Churg Strauss will experience neurological symptoms, including polyneuropathy.


The exact cause of Churg Strauss is unknown. Like other autoimmune disorders, researchers believe that several factors, such as genetics and environment, play a role in "triggering" the immune system.

The disease is very rare. Estimates range from two to 15 people per million diagnosed each year. It occurs equally in men and women. While the symptoms of Churg Strauss can begin at any age, most cases are diagnosed when patients are between the ages of 30–50.


Churg Strauss is diagnosed based on a thorough history of a patient's symptoms, X-rays and CT scans, and blood tests to check the levels of eosinophils. Sometimes tissue biopsies are taken to look for high levels of eosinophils in specific organs.

The American College of Rheumatology set the following diagnostic criteria for Churg Strauss to help clinicians differentiate it from other types of vasculitis:

  1. Asthma
  2. Eosinophilia
  3. Mono- or polyneuropathy
  4. Nonfixed pulmonary infiltrates
  5. Abnormality of the paranasal sinuses (e.g. nasal polyps)
  6. Extravascular eosinophilia


Churg Strauss Syndrome can be fatal if left untreated. Complications from chronic vasculitis can increase a person's risk for developing serious conditions such as aneurysms, heart disease, and stroke. Diagnosing the condition early and beginning treatment can help reduce inflammation and prevent the progression to more serious symptoms.

Treatment for Churg Strauss depends on the phase the condition is in at the time of diagnosis, which organ systems are affected, and the patient's individual symptoms. Most patients will begin treatment with medications that suppress their immune system, called corticosteroids. One of the most commonly prescribed corticosteroid or steroid medications is prednisone.

More than 90 percent of patients are able to manage their symptoms and even achieve complete remission with steroid therapy alone.

Patients with advanced disease may also need to take cytotoxic medications such as cyclophosphamide or methotrexate.

A Word From Verywell

While Churg Strauss is not a very common condition—only about 2 in a million people are diagnosed each year—it is a very serious condition that can have potentially fatal complications if left untreated. However, once diagnosed, it can be successfully treated using steroid therapy and many patients achieve complete remission from their symptoms.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Abby Norman
Abby Norman is a freelance science writer and medical editor. She is also the author of "Ask Me About My Uterus: A Quest to Make Doctors Believe in Women's Pain."