Patients with eosinophilia have an abnormally high number of eosinophils, a type of white blood cell, in their blood. Eosinophilia is not a type of cancer but it often occurs in reaction to something else in the body. High levels of eosinophils indicate that the body may be reacting to an allergen or parasite, or to substances produced by the cells of cancers such as Hodgkin’s disease and chronic myeloid leukemia. Thus, eosinophilia is most commonly a reaction to a disease process rather than a specific disease itself.
Eosinophilic leukemia is a rare cause of eosinophilia; it is treated similarly to other forms of acute leukemia. Treatments are generally aimed at the underlying allergic, parasitic, or malignant disorder.