[Hypereosinophilic syndrome].

Hypereosinophilic syndrome is a heterogeneous group of diseases characterized by blood hypereosinophilia and eosinophil-related organ damage. A comprehensive diagnostic work-up is necessary to identify underlying conditions and to detect organ involvement, which are important for prognosis. Involvement of the heart is related with a poorer outcome. Some underlying conditions can be treated with targeted therapies, e.g., tyrosine kinase inhibitors. However, glucocorticoids in combination with steroid-sparing drugs are generally used for treatment. Furthermore, the growing understanding of the molecular pathogenesis will lead to new therapies, e.g., the use of anti-cytokine antibodies.