In 1990, the American College of Rheumatology (ACR) proposed the following six criteria for the diagnosis of Churg-Strauss syndrome [5]:

• Asthma
• Eosinophilia (> 10%)
• Sinusitis
• Pulmonary infiltrates (may be transient)
• Histological proof of vasculitis
• Neuropathy

The presence of 4 or more of these criteria is diagnosic of the disease [5].

Other common manifestations of Churg-Strauss syndrome are [1] [6]:

• Weight loss
• Fever
• Myalgia
• Skin involvement
• Arthralgia
• Gastrointestinal symptoms

Churg-Strauss syndrome has 3 phases: allergic (rhinitis and asthma), eosinophilic infiltrative disease, and systemic vasculitis.

Laboratory Studies

• Complete blood count shows eosinophilia (usually at least 10% or 5000-9000 eosinophils/µL), and mild anemia.
• Erythrocyte sedimentation rate (ESR) is elevated.
• C-reactive protein (CRP) levels are also elevated.
• Renal tests - Elevated serum blood urea nitrogen (BUN) and creatinine levels in cases of renal involvement .
• Antineutrophil cytoplasmic antibodies (ANA) are present in approximately 40% of patients.
• Serum IgE levels are elevated.
• Rheumatoid factor is elevated at low titer levels.

Urinalysis shows abnormal urine sediment, proteinuria, microscopic hematuria, and red blood cell casts with renal involvement.

Imaging

Pulmonary opacities can be found in 26 - 77% of cases. Pulmonary infiltrates may be transient [2]. Computer Assisted Tomography (CT) findings include areas of consolidation similar to that of chronic pneumonia. Bronchial dilatation and wall thickening may also be seen [2].

Other tests may be indicated for specific organ-system involvement:

• Electrocardiogram for cardiac manifestations.
• Gastrointestinal endoscopy for gastrointestinal bleeding.
• Electromyelography (EMG) and nerve conduction studies for peripheral neuropathies.

Biopsy

If local organ involvement exists, obtaining a biopsy of that organ is helpful in confirming the diagnosis. Biopsies of skin, lung,
kidney, nerve, or muscle may be indicated.

Churg-Strauss syndrome is a systemic disorder that involves multiple organ systems. Therefore, the type of treatment required depends on the type of organ system involvement.

Glucocorticoids alone are usually adequate for the treatment of Churg-Strauss syndrome. Corticosteroids modify the immune response. Oral prednisone is usually sufficient to control the vasculitis.

Cytotoxic drugs are necessary in less than 20% of patients [8]. Cytotoxic agents inhibit cell growth and proliferation of eosinophils. They are reserved for cases that do not respond to corticosteroids. Cyclophosphamide (Cytoxan, Neosar) is the drug most often used.

With treatment, the 1-year survival rate is 90% and the 5-year survival rate is 62%.

Churg and Strauss first described the syndrome in 1951. They found the disorder in 13 patients who had asthma as well as eosinophilia, inflammation, systemic vasculitis, and glomerulonephritis [3].

The cause of Churg-Strauss syndrome is unknown. However, the presence of hypergammaglobulinemia, increased levels of immunoglobulin E (IgE), rheumatoid factor, and anti-neutrophil cytoplasmic antibody, [4] in these patients suggested an allergic autoimmune disorder.

The incidence of Churg-Strauss syndrome in the United States is 1 to 3 cases per 100,000 adults per year [2]. The international incidence of Churg-Strauss syndrome is approximately 2.5 cases per 100,000 adults per year [2].

Churg-Strauss syndrome is slightly more common in males than in females.

The age at onset varies from 15-70 years, with a mean age of approximately 38 years.

Churg-Strauss syndrome is a systemic vasculitis in which the lung is the predominant, but not the only, site of inflammation. Churg-Strauss syndrome is a rare form of systemic vasculitis occurring only in patients with asthma [5].

The vascular inflammation in the disorder results from a prolonged life of eosinophils in these individuals. Although the exact mechanisms involved in Churg-Strauss syndrome have not been identified, it seems to be the secretion eosinophil-activating cytokines  [4] by T-lymphocytes that is the stimulating factor.

Differential diagnoses include Wegener's granulomatosis and other forms of systemic vasculitis [6]. Some recent studies show Churg-Strauss syndrome developing when oral steroid doses are reduced and a leukotriene receptor antagonist (montelukast, zafirlukast) is added [7].

There are no guidelines for prevention of Churg-Strauss syndrome.

Churg-Strauss syndrome is a rare, systemic vasculitis that affects small- to medium-sized arteries and veins. It is a multi-system disorder that affects primarily the respiratory system, but can also involve the cardiovascular and renal systems.

Churg-Strauss syndrome is characterized by a history of asthma, elevated eosinophilia count, and necrotizing vasculitis with inflammation [1].

The long-term prognosis for Churg-Strauss syndrome is good. Most patients need low dose oral corticosteroids for persistent asthma. Some need continued anti-inflammatory medication for many years after clinical recovery from vasculitis [1] to prevent recurrence.

The principal cause of morbidity and mortality in Churg-Strauss syndrome is myocarditis and myocardial infarction, secondary to coronary arteritis [2].

What is Churg-Strauss syndrome?

Churg-Strauss syndrome is a rare disorder that may affect multiple organ systems, especially the lungs. It is a type of vasculitis (blood vessel inflammation) that occurs throughout the body.

It is an auto-immune disorder, meaning the body's white blood cells, which usually fight off infection, begin attacking healthy tissue.

Churg-Strauss syndrome occurs almost always in individuals who have a history of asthma.

What are the symptoms of Churg-Strauss syndrome?

Churg-Strauss Syndrome has many symptoms involving many different organ systems. A person with Churg Strauss syndrome may have some or all of the following symptoms [9]:

• Asthma
• Elevated white blood cell count, specifically eosinophils
• Neuropathy, pain, numbness, or tingling in hands and feet
• Lung adhesions or scarring
• Chronic sinusitis and nasal polyps
• Inflammation within blood vessels

Besides the symptoms listed above, the person with Churg Strauss syndrome may also have:

• Nodules or purpura (purplish blotches) on the skin,
• Damage to the kidneys, heart, or other organs because of inflammation of their blood vessels,
• Generalized flu-like symptoms, such as weakness, fatigue, loss of appetite, fever, and muscle pain (myalgia),
• Serious organ damage and potentially life-threatening complications.

Who gets Churg-Strauss syndrome?

Most people with Churg-Strauss Syndrome have a history of asthma or other allergy. Usually, a person already has asthma when they develop Churg Strauss syndrome.

The systemic symptoms may follow an allergic reaction by six months or more.
Churg-Strauss Syndrome affects all age groups, but children more commonly. Males and females are equally affected.

How is Churg-Strauss syndrome treated?

Churg-Strauss Syndrome is an autoimmune disorder. This means that the body’s immune system mistakenly attacks itself.

Treatment is aimed at slowing the immune response. The most commonly used medication is prednisone, an immunosuppressant. It is given orally, except in severe cases when it is given intravenously. The medication usually works in a few days. But since the symptoms may recur, medication may need to continue long-term.

1. Guillevin L, Cohen P, Gayraud M, et al. Churg-Strauss syndrome. Clinical study and long-term follow-up of 96 patients. Medicine (Baltimore). Jan 1999;78(1):26-37.
2. Choi YH, Im JG, Han BK, Kim JH, Lee KY, Myoung NH. Thoracic manifestation of Churg-Strauss syndrome: radiologic and clinical findings. Chest. Jan 2000;117(1):117-24.
3. Churg J, Strauss L. Allergic granulomatosis, allergic angiitis, and periarteritis nodosa. Am J Pathol. Mar-Apr 1951;27(2):277-301.
4. Hellmich B, Ehlers S, Csernok E, Gross WL. Update on the pathogenesis of Churg-Strauss syndrome. Clin Exp Rheumatol. Nov-Dec 2003;21(6 Suppl 32):S69-77.
5. Masi AT, Hunder GG, Lie JT, et al. The American College of Rheumatology 1990 criteria for the classification of Churg-Strauss syndrome (allergic granulomatosis and angiitis). Arthritis Rheum. Aug 1990;33(8):1094-100.
6. Schmitt, W. H., Linder, R., Reinhold-Keller, E. and Gross, W. L. (2001), Improved differentiation between Churg-Strauss syndrome and Wegener's granulomatosis by an artificial neural network. Arthritis & Rheumatism, 44: 1887–1896.
7. Franco J, Artes MJ. Pulmonary eosinophilia associated with montelukast. Thorax. Jun 1999;54(6):558-60.
8. Tsurikisawa, N., Taniguchi, M., Suzuki, S. and Akiyama, K. (2003), Effects of a nitro compound patch on neuropathy in Churg-Strauss syndrome. Allergy, 58: 686–687.
9. Jennette JC, Falk RJ, Andrassy K, et al. Nomenclature of systemic vasculitides. Proposal of an international consensus conference. Arthritis Rheum. Feb 1994;37(2):187-92.