Skip to Content

Hypereosinophilic Syndrome


Hypereosinophilic syndrome (HES) is a group of conditions that causes you to have too many eosinophils. An eosinophil is a type of white blood cell. Allergies, asthma, parasitic infections, and certain medicines may increase the number of eosinophils. Organs such as your skin, lungs, heart, or brain may be damaged if you have too many eosinophils. They may also harm your kidneys, intestines, liver, or spleen.


Informed consent



  • Immune modifying medicine decreases the number of eosinophils in your blood.
  • Steroids decrease pain and inflammation. They may also decrease the number of eosinophils in your blood and prevent further damage.


  • Blood tests will be done to measure the number eosinophils and other white blood cells.
  • Your bowel movement may be tested to see if you have parasites.
  • A chest x-ray is done to look at your heart and lungs.
  • An echocardiogram is a type of ultrasound. Sound waves are used to show the structure and function of your heart. It may be done to check for damage to your heart from HES.
  • A bone marrow biopsy is a procedure to remove a sample of bone marrow to be tested.


A bone marrow transplant is a procedure to replace your diseased bone marrow with healthy marrow. Bone marrow usually comes from a donor. The bone marrow is given to you in an IV while you are in the hospital.


Medicines or a bone marrow transplant may increase your risk for bleeding or infection. Ask your healthcare provider for more information about a bone marrow transplant.



