Chronic eosinophilic leukemia is a disease in which too many white blood cells (eosinophils) are made in the bone marrow.
Eosinophils are white blood cells that react to allergens (substances that cause an allergic response) and help fight infections caused by certain parasites. In chronic eosinophilic leukemia, there are too many eosinophils in the blood, bone marrow, and other tissues. Chronic eosinophilic leukemia may stay the same for many years or it may progress quickly to acute leukemia.
Possible signs of chronic eosinophilic leukemia include fever and feeling very tired.
Chronic eosinophilic leukemia may not cause early symptoms. It is sometimes found during a routine blood test. The following symptoms may be caused by chronic eosinophilic leukemia or by other conditions. Check with your doctor if you have any of the following problems: