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CHURG-STRAUSS SYNDROME

The syndrome of allergic granulomatosis and angiitis is a disorder characterized by pulmonary and systemic small vessel vasculitis, extravascular granulomas, and hypereosinophilia occurring in individuals with asthma and allergic rhinitis.

Clinical Features

Lanham identified three phases of the disease. A prodromal period, which may last for years (more than 30 years), consists of allergic manifestations of allergic rhinitis and nasal polyposis, frequently followed by asthma. The second phase of the disease is characterized by peripheral blood and tissue eosinophilia (with Loffler's syndrome), chronic eosinophilic pneumonia.

The eosinophilic infiltrative disease may remit and recur over years before the systemic vasculitis appears, thereby defining the third phase of the disease, although these three phases do not necessarily have to follow one another.

Systemic vasculitis emerges with a mean delay of 3 years after the onset of asthma. A shorter duration of asthma prior to the onset of vasculitis is generally associated with a poorer prognosis. General symptoms, such as fever or weight loss, are present in most patients, and their development in asthmatic patients is suggestive.

Asthma is a central feature of Churg-Strauss syndrome and precedes the systemic manifestations in nearly all cases. In comparison with common asthma, it begins relatively late during life, at the age of 35.

Pulmonary infiltrates may be present in nearly half the cases in the second phase of the disease, usually in association with asthma and hypereosinophilia mimicking chronic eosinophilic pneumonia. The radiologic features of pulmonary infiltrates are diverse: transient and patchy alveolar infiltrates without lobar or segmental distribution.

Cutaneous Lesions

Purpura or nodules occur in approximately two thirds of the patients and reflect the preferential involvement.

Neuropathy

Peripheral neuropathy, usually mononeuritis multiplex, is found in 64% to 75% of the patients. Its aspect is similar to that of PAN. CNS involvement is as frequent as in PAN.

Musculoskeletal Involvement

Polyarthralgias and arthritis frequently occur during the vasculitic phase of the disease. Any joint may be involved, and arthralgias are often migratory. Myalgias are common.

Cardiac Involvement

Cardiac involvement is common in Churg-Strauss syndrome and represents a major cause of mortality. It may consist of congestive heart failure, severe pump insufficiency, pericardial effusion, or restrictive cardiomyopathy.

Gastrointestinal Involvement

GI tract symptoms occur in 37% to 62% of the patients. They include abdominal pain, diarrhea, and GI bleeding. Two different mechanisms of involvement are possible. Mesenteric vasculitis is the most frequent and shares the

Renal Involvement

Renal involvement is present in 16% to 49% of the patients. The characteristic glomerular lesion of Churg-Strauss syndrome is focal segmental glomerulonephritis with necrotizing features including crescents. Necrotizing glomerulonephritis is 

TREATMENT

PAN and MPA are severe systemic vasculitides whose prognoses have been transformed by corticosteroids and immunosuppressive drugs, especially cyclophosphamide (CY). Since their initial use3 in 1950 to treat PAN, corticosteroids alone increased the 5-year survival rate of 10% for untreated patients to approximately 55% in the mid-to-late 1970s. Survival was further prolonged by adding a second immunosuppressant, to the treatment regimen, so attaining a 5-year survival rate of 82% for patients given corticosteroids and

Because the initial treatment of PAN was controversial, several prospective therapeutic studies were conducted in France to define the most effective and safest treatment for PAN. The outcome in PAN and other systemic vasculitides is dependent on the extent of 

Management decisions should be based on the anatomic distribution, severity of involvement, and intensity of disease activity. The choice of first-line treatment may be helped by using well-established severity indicators and prognostic factors.

Polyarteritis Nodosa without Hepatitis B Viral Infection and Microscopic Polyangiitis

The initial management of PAN without HBV infection should include high dose of corticosteroid preparations. The administration of methylprednisolone pulses (usually 15 mg/kg intravenously over 60 minutes, repeated at 24-hour

Hepatitis B Virus-Related Polyarteritis Nodosa

In HBV-related PAN, conventional treatment with corticosteroids and CY jeopardize the patient's outcome by allowing the virus to persist, thereby favoring its replication and facilitating evolution toward chronic hepatitis and liver cirrhosis. Based on the efficacy of antiviral agents in chronic hepatitis, we combined both therapies to treat HBV-related PAN. The rationale of the therapeutic sequence was to obtain the following effects: initial corticosteroids to rapidly control the most severe life-threatening manifestations of PAN that are common during the

Churg-Strauss Syndrome

Because Churg-Strauss syndrome responds well to corticosteroids, and is the treatment of choice, a regimen similar to that for PAN should be employed. In Churg-Strauss syndrome, however, it is often impossible to stop

OUTCOME

Vasculitides of the PAN group are acute or subacute diseases, and it is possible to successfully treat patients and to definitively stop treatment. Nevertheless, relapses can occur. They are rare in HBV-related PAN and c-PAN (10%) but more frequent in MPA (35%). Relapses are usually of mild intensity but are, in rare cases, more severe than the