Pediatric Hypereosinophilic Syndrome
Hypereosinophilic syndrome varies from an asymptomatic phenomenon to a life-threatening multisystem disease. It is characterized by an eosinophil count of more than 1500/μ L (usually many more) for more than 6 months and multiorgan involvement in the absence of other causes of eosinophilia and in the absence of eosinophil blast cells in the marrow or blood. Three subtypes are recognized: myeloproliferative, lymphocytic, and idiopathic. Hypereosinophilic syndrome is very rare in children.