An increased production of white blood cells to fight an infection; A reaction to a drug that increases white blood cell production; A disease of bone marrow, causing abnormally high production of white blood cells; An immune system disorder that increases white blood cell production; Specific causes of a high white blood cell count include: Acute lymphocytic leukemia. Acute myelogenous leukemia (AML) Allergy, especially severe allergic reactions. Chronic lymphocytic leukemia. Chronic myelogenous leukemia. Drugs, such as corticosteroids and epinephrine. Infections, bacterial or viral.