Eosinophils are a type of white blood cell that destroy foreign substances in the body and regulate inflammation as part of the body’s immune function. Too much eosinophil inflammation results in tissue damage. Common triggers are parasites, allergies, and some autoimmune disorders. Generally, diagnosing and treating the underlying disease resolves the eosinophil problem.
Eosinophils are a necessary part of the body’s immune function. They destroy foreign substances in the body and regulate inflammation. A type of white blood cell, eosinophils increase in number when the body faces allergic responses, skin inflammation, and infection due to parasites. Eosinophil counts sometimes increase due to bone marrow disorders.
The body’s tissue and mucus contains eosinophils, as do other parts of the body. A blood test identifies blood eosinophilia, where there is an excess of eosinophils. However, in cases of tissue eosinophilia, blood counts may be normal. A blood count of over 500 eosinophils per microliter generally indicates eosinophilia in adults, and counts over 1,500 that last for several months indicate the presence of hypereosinophilic syndrome.1
While eosinophils play a vital role in the body’s health, their inflammation function sometimes gets out of control. Inflammation is a necessary part of immune responses, isolating and containing the area where disease or infection occurs. When too much inflammation occurs, other issues arise, sometimes resulting in tissue damage.
Diseases and conditions known to cause Eosinophilia include2:
- Fungal diseases
- Allergies to foods, medications, and seasonal substances
- Adrenal problems
- Skin disorders
- Exposure to toxic substances
- Hodgkin's lymphoma
- Certain leukemias, including Chronic myelogenous leukemia and Eosinophilic leukemia
- Autoimmune disorders such as lupus, Crohn’s Disease
- Endocrine disorders
- Some cancers and tumors
In some cases, bone marrow produces too many eosinophils. One condition, Idiopathic hypereosinophilic syndrome (HES), causes overly high eosinophil counts with no known cause. Hypereosinophilic syndrome may be the result of certain cancers, including bone marrow or lymph node cancer.3
Generally, treating eosinophil issues means properly diagnosing and treating the underlying disease. For instance, treating eosinophilic esophagitis, a chronic allergic inflammatory disease of the esophagus, involves identifying the food allergens causing the inflammation and removing them from the diet.4
Airway inflammation caused by eosinophils plays a huge part in asthma attacks, and researchers now seek development of therapies that actually reduce asthma patients’ eosinophil count
With proper treatment for the condition that brought on the excess production of eosinophils, they generally decrease in number. However, many require supportive care during treatment, which varies depending upon the underlying condition. When hospitalization is required, general supportive therapies are administered, from IV fluids to drugs for pain management. Most cases of secondary eosinophilia are treated according to their underlying causes. Pulmonary eosinophilia may require oxygen treatments. According to Medscape
, when allergies cause the problem, corticosteroid treatment may work, although use of such medications may worsen infections due to parasites and fungi. In cases involving steroid resistant diseases, interferon may be used, in addition to several other medications that control organ involvement.
Proper treatment of eosinophilia requires proper diagnosis of its cause. Only then can proper treatment take place.
The information on this page is not intended to be a substitute for professional medical advice, diagnosis, or treatment. For more information about eosinophilic disorder, talk to your doctor or primary care provider.
Page last updated: October 14, 2018