Churg-Strauss syndrome presenting with pulmonary capillaritis and diffuse alveolar hemorrhage

Churg-Strauss syndrome (CSS) is a rare disorder characterized by the histopathological triad of systemic necrotizing vasculitis, extravascular granuloma, and eosinophilic infiltrate, occurring in individuals with asthma or a history of allergy. We report a case of CSS with rare presentation of diffuse pulmonary hemorrhage. A transbronchial lung biopsy showed necrotizing vasculitis, pulmonary capillaritis, and prominent eosinophilic infiltrate. At autopsy, necrotizing granuloma and diffuse alveolar hemorrhage were found in the lungs. Laboratory data showed hypereosinophilia, disseminated intravascular coagulopathy, and positive anti-proteinase 3 antineutrophil cytoplasmic antibody (ANCA). This case emphasize that CSS should be considered in the differential diagnosis of ANCA-positive vasculitis with diffuse alveolar hemorrhage.