Last updated: January 20, 2015
Synonyms: Allergic angiitis and granulomatosis
ICD9 Code: 446.4
ICD10 Code: M30.1
Definition: Churg-Strauss angiitis is granulomatous vasculitis of small and medium-sized vessels associated with pulmonary disease and hypereosinophilia.
Etiology: This systemic vasculitis is of uncertain etiology.
Pathology: Churg-Strauss angiitis is necrotizing vasculitis with prominent eosinophilic tissue infiltrates and granulomas involving both medium and small arteries, capillaries, and venules.
Demographics: This very rare disorder is more prevalent in middle-aged men with antecedent asthma and rhinitis.
Cardinal Findings: Asthmatic manifestations with fluctuating pulmonary infiltrates (resembling Loeffler ’s syndrome), chronic eosinophilic pneumonia, and eosinophilic gastroenteritis may antedate frank vasculitis. Vasculitis may present with worsening respiratory status accompanied by systemic manifestations similar to those of polyarteritis nodosa (PAN). These include severe constitutional symptoms, arthralgias, mononeuritis multiplex, and occasional cardiac or gastrointestinal symptoms. Lung and skin findings are more common in Churg-Strauss angiitis than in PAN.
Uncommon Findings: In contrast to PAN, glomerulonephritis is not usually seen, and renal disease is present in only 40% of patients. In contrast to Wegener ’s granulomatosis, in Churg-Strauss angiitis the pulmonary lesions seldom cavitate, and the upper airway disease is less destructive.
Diagnostic Testing: Nonspecific measures of systemic inflammation include elevated acute-phase reactants (ESR and/or CRP), leukocytosis, anemia of chronic inflammation, and thrombocytosis. Peripheral blood eosinophilia and elevated IgE levels are often present. Circulating immune complexes, hypocomplementemia, and hyperglobulinemia have been observed but do not aid in the differential diagnosis. P-ANCA is occasionally present. A diagnosis is strongly supported by histopathologic evidence of small and medium vessel angiitis with eosinophils.
Keys to Diagnosis: The presentation is similar to that of PAN but with concomitant pulmonary involvement and a strong allergic component.
Diagnostic Criteria: 1990 ACR criteria include (a) asthma; (b) eosinophilia (>10% on WBC differential); (c)mononeuropathy or polyneuropathy; (d) migratory or transient pulmonary infiltrates; (e) paranasal sinus abnormalities; and (f) extravascular eosinophils on biopsy of a blood vessel. The presence of 4 or more of these 6 criteria constitutes a diagnosis for the purposes of classification (85% sensitivity; 99.7% specificity). A history of allergy is a criterion in other classification systems.
Therapy: High-dose corticosteroids are used (>1 mg/kg prednisone, occasionally started using a 1-g bolus of methylprednisolone). Cytotoxic therapy with cyclophosphamide or less commonly azathioprine is often used initially or added later as a steroid-sparing agent.
Prognosis: Survival is slightly better than in polyarteritis nodosa, with up to 90% of patients alive 1 year after the diagnosis.
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