Eosinophils are a type of white blood cell. They help fight off infections and play a role in your body's immune response. They can also build up and cause inflammation.
Normally your blood doesn't have a large number of eosinophils. Your body may produce more of them in response to
Allergic disorders
Skin conditions
Parasitic and fungal infections
Autoimmune diseases
Some cancers
Bone marrow disorders
In some conditions, the eosinophils can move outside the bloodstream and build up in organs and tissues. This can happen in many different parts of the body, including the esophagus, heart, lungs, blood, and intestines. Treatment of eosinophilic disorders can vary, depending on the cause and which part of the body is affected. Steroids are often part of the treatment.