Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic Granulomatosis with Polyangiitis (EGPA), previously called Churg-Strauss syndrome (CSS), is a multisystemic necrotizing vasculitis. It belongs to small to medium size vessel anti-neutrophil cytoplasmic antibody (ANCA) vasculitis. EGPA is characterized by allergic rhinitis, asthma, and peripheral eosinophilia. Involvement of non-pulmonary organs, including the gastrointestinal tract, kidney, and heart, is not uncommon and has been associated with poor prognosis as assessed by the revised Five-Factor Score (FFS). Approximately 10 percent of vasculitis are recognized to have EGPA, although the epidemiology of EGPA remains unclear. The exact etiology is unknown. Augmented Th1 and Th2 lymphocyte function, increased eosinophil recruitment, and decreased eosinophil apoptosis are postulated as underlying pathogenesis. Diagnosis includes peripheral blood eosinophilia, usually 5000-9000 eosinophils/microL, and is confirmed by lung or skin biopsy showing leukoclastic vasculitis. ANCA antibodies are detected in about 40-60 percent of patients. The primary treatment of EGPA is systemic glucocorticoids which has shown to improve 5-year survival rates to 70-90%.