eosinophilia

eosinophilia An abnormally high number of eosinophils in the blood. Normally, eosinophils constitute 1 percent to 3 percent of the peripheral blood leukocytes, at a count of 350 to 650 per cubic millimeter. In areas of the world where parasite diseases are common, they are the usual cause of eosinophilia. In developed nations, eosinophilia is most often due to allergy or, less often, a drug reaction. Other causes of eosinophilia are numerous, but less common. See also eosinophil.