A high eosinophils count can result from allergies, environmental toxins, autoimmune diseases, parasitic infections and fungal infections, explains Mayo Clinic. Other potential causes include skin disorders, tumors, endocrine illnesses and conditions affecting the adrenal glands.
A wide range of diseases and conditions can cause eosinophil levels to rise, with allergic reactions and parasitic infections being especially common causes, notes Mayo Clinic. Examples of specific conditions known to increase eosinophil levels include lupus, ovarian cancer, Chron's disease, allergic reactions to drugs and asthma. The roundworm infection ascariasis, myelogenous leukemia, eczema, hay fever and Hodkin's lymphoma are other possible causes. Additionally, doctors sometimes diagnose patients with idiopathic hypereosinophilic syndrome, a condition in which eosinophil levels are extremely high without an identifiable cause.
The medical term for a high eosinophils count is eosinophilia, as Mayo Clinic explains. Blood eosinophilia occurs when there are more eosinophils in the blood than normal, while tissue eosinophilia occurs when there is a high concentration of eosinophils in a particular area of tissue where there is infection or inflammation. Eosinophils are one type of white blood cell, and their function in the body is to ward off disease. They perform this function by consuming harmful foreign substances and promoting inflammation.