[Churg-Strauss syndrome (allergic granulomatous angiitis). Classical data and new questions].

The Churg-Strauss syndrome is a vasculitis which can involve all the organs and is associated with eosinophil necrotising vasculitis and eosinophil granuloma infiltrations. Asthma is a constant clinical feature. It is cortico-dependent and can be very severe. Laboratory signs include a variety of pulmonary images on chest X-ray and hypereosinophilia which can be major and variable over time. These lesions are associated with vasculitis lesions which can involve several different sites. The syndrome has more or less defined nosological limits excluding non-eosinophilic vasculitis and the group of hypereosinophilic diseases involving little or no manifestations of vasculitis. Corticosteroid therapy is the essential treatment of this syndrome and greatly changes the prognosis.