Churg-Strauss syndrome




Churg–Strauss syndrome (CSS) is an autoimmune condition that causes inflammation of small and medium-sized blood vessels (vasculitis) in persons with a history of airway allergic hypersensitivity (atopy). It usually manifests in three stages. The early (prodromal) stage is marked by airway inflammation; almost all patients experience asthma and/or allergic rhinitis. The second stage is characterized by abnormally high numbers of eosinophils (hypereosinophilia), which causes tissue damage, most commonly to the lungs and the digestive tract. The third stage consists of vasculitis, which can eventually lead to cell death and can be life-threatening.


Churg–Strauss syndrome consists of three stages, but not all patients develop all three stages or progress from one stage to the next in the same order; whereas some patients may develop severe or life-threatening complications such as gastrointestinal involvement and heart disease, some patients are only mildly affected, e.g. with skin lesions and nasal polyps. Churg–Strauss syndrome is consequently considered a highly variable condition in terms of its presentation and its course.

Allergic stage

The prodromal stage is characterized by allergy. Almost all patients experience asthma and/or allergic rhinitis, with more than 90% having a history of asthma that is either a new development, or the worsening of pre-existing asthma, which may require systemic corticosteroid treatment. On average, asthma develops from three to nine years before the other signs and symptoms.

The allergic rhinitis may produce symptoms such as rhinorrhea and nasal obstruction, and the formation of nasal polyps that require surgical removal, often more than once. Sinusitis may also be present.

Epsinophilic stage

The second stage is characterized by an abnormally high level of eosinophils (a type of white blood cell) in the blood and tissues. The symptoms of hypereosinophilia depend on which part of the body is affected, but most often it affects the lungs and digestive tract. The signs and symptoms of hypereosinophilia may include weight loss, night sweats, asthma, cough, abdominal pain, and gastrointestinal bleeding. Fever and malaise are often present.

The eosinophilic stage can last months or years, and its symptoms can disappear, only to return later. Patients may experience the third stage simultaneously.

Vasculitic stage

The third and final stage, and hallmark of Churg–Strauss syndrome, is inflammation of the blood vessels, and the consequent reduction of blood flow to various organs and tissues. Local and systemic symptoms become more widespread and are compounded by new symptoms from the vasculitis.

Severe complications may arise. Blood clots may develop within the damaged arteries in severe cases, particularly in arteries of the abdominal region, which is followed by infarction and cell death, or slow atrophy. Many patients experience severe abdominal complaints; these are most often due to peritonitis and/or ulcerations and perforations of the gastrointestinal tract, but occasionally due to acalculous cholecystitis or granulomatous appendicitis.

The most serious complication of the vasculitic stage is heart disease, which is the cause of nearly one-half of all deaths in patients with Churg–Strauss syndrome. Among heart disease-related deaths, the most usual cause is inflammation of the heart muscle caused by the high level of eosinophils, although some are deaths to inflammation of the arteries that supply blood to the heart or pericardial tamponade. Kidney complications have been reported as being less common.


Churg-Strauss syndrome is rare. The cause of the syndrome is not known, but it involves an abnormal over-activation of the immune system in a person with underlying bronchospastic lung disease (asthma). While Churg-Strauss syndrome has been reported to be associated with certain asthma medications, called leukotriene modifiers, whether they actually cause the disease or whether the patients that take them have more severe asthma that lends a tendency toward the development of Churg-Strauss is not yet clear.


Diagnostic markers include eosinophil granulocytes and granulomas in affected tissue and antineutrophil cytoplasmic antibodies against neutrophil granulocytes. The American College of Rheumatology 1990 criteria for diagnosis of Churg–Strauss syndrome lists these criteria:

  • Asthma
  • Eosinophils greater than 10% of a differential white blood cell count
  • Presence of mononeuropathy or polyneuropathy
  • Unfixed pulmonary infiltrates
  • Presence of paranasal sinus abnormalities
  • Histological evidence of extravascular eosinophils

For classification purposes, a patient shall be said to have Churg–Strauss syndrome (CSS) if at least four of these six criteria are positive. The presence of any four or more of the six criteria yields a sensitivity of 85% and a specificity of 99.7%.


Churg-Strauss syndrome is a serious disease that can be fatal. Untreated it is extremely dangerous and threatens the organs that are affected. With aggressive treatment and monitoring it can be quieted and total inactivation of the disease (remission) is possible.


Treatment for Churg–Strauss syndrome includes glucocorticoids (such as prednisolone) and other immunosuppressive drugs (such as azathioprine and cyclophosphamide). In many cases, the disease can be put into a type of chemical remission through drug therapy, but the disease is chronic and lifelong.

A systematic review conducted in 2007 indicated all patients should be treated with high-dose steroids, but in patients with a five-factor score of one or higher, cyclophosphamide pulse therapy should be commenced, with 12 pulses leading to fewer relapses than six. Remission can be maintained with a less toxic drug, such as azathioprine or methotrexate.