Eosinophils are a type of white blood cell that play a key part in the body's immune system 2. They are responsible for fighting off invasions from other organisms, such as parasites and viruses. Eosinophils are made in the body's bone marrow, and then circulate around the body via the blood 2. During a blood test, health care providers check for eosinophil levels. High levels are a warning sign that the body's immune system is quite active. Low eosinophil levels are preferred, according to Net Wellness.
If you are experiencing serious medical symptoms, seek emergency treatment immediately.
Successful Control of Allergies
Allergic or atopic disorders trigger eosinophils to increase throughout the body 2. For example, when someone is affected by hay fever, there are increased levels of eosinophils in the nasal passages, notes CincinnatiChildrens.org 2. When a person's allergic condition is well-managed, these white blood cell levels are low. Over-the-counter or prescription antihistamines can control the body's reaction to allergens, thereby signaling the body that the production of eosinophils in the bone marrow are not necessary, according to CincinnatiChildrens.org 2.
Proper Asthma Management
Causes of an Elevated White Blood Cell Count
When a patient experiences an asthma attack, the eosinophils are not properly released and accumulate in the lungs 2. They release toxins to combat intruders, but instead inflame the tissues of the lungs. Steroid medication is generally successful in eliminating this process, so when a patient's asthma is being managed properly via rescue inhaler and other medications, the eosinophil count is low, notes Global Net 2. Managing a patient's asthma can also eliminate long-term damage to the lungs from an overabundance of eosinophil toxins.
Absence of Conditions
- low levels of eosinophils means that the body is not likely to be engaged in fighting off illnesses
- a blood test may help rule out several conditions
- including certain drug reactions
- immunologic disorders
- blood disorders
- endocrine problems
- parasitic infestations
- infectious diseases
- according to Merck 2
When high concentrations of eosinophil is discovered in tissue, such as the nasal passages, it can give heath care workers a clue about what could be wrong. When eosinophil levels are found to be elevated, it gives health care workers more clues about what might be causing varying levels.
Causes of an Elevated White Blood Cell Count
The Effect of Asthma on RBC Count
White Blood Cells & Their Functions
Blood Cell Count & Infections
Diseases That Lower White Blood Cells
How to Read CBCD Blood Test Results
Types of Leukocytes
What Are the Four Types of Antibodies?
Signs & Symptoms of Low Monocytes Blood Cell Count
Five Types of White Blood Cells
- Cincinnati Children's: Eosinophil History
- Global Net: Eosinophils
- Cincinnati Children's: Conditions
- Blumenreich MS. The White Blood Cell and Differential Count. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 153. Available from: https://www.ncbi.nlm.nih.gov/books/NBK261/
- Mehta P, Furuta GT. Eosinophils in Gastrointestinal Disorders: Eosinophilic Gastrointestinal Diseases, Celiac Disease, Inflammatory Bowel Diseases, and Parasitic Infections. Immunol Allergy Clin North Am. 2015;35(3):413–437. doi:10.1016/j.iac.2015.04.003
- Ramirez GA, Yacoub MR, Ripa M, et al. Eosinophils from Physiology to Disease: A Comprehensive Review. Biomed Res Int. 2018;2018:9095275. Published 2018 Jan 28. doi:10.1155/2018/9095275
- Shamri R, Xenakis JJ, Spencer LA. Eosinophils in innate immunity: an evolving story. Cell Tissue Res. 2011;343(1):57–83. doi:10.1007/s00441-010-1049-6
- Kovalszki A, Weller PF. Eosinophilia. Prim Care. 2016;43(4):607–617. doi:10.1016/j.pop.2016.07.010
- Long H, Zhang G, Wang L, Lu Q. Eosinophilic Skin Diseases: A Comprehensive Review. Clin Rev Allergy Immunol. 2016;50(2):189–213. doi:10.1007/s12016-015-8485-8
- Beishuizen A, Vermes I, Hylkema BS, Haanen C. Relative eosinophilia and functional adrenal insufficiency in critically ill patients. Lancet. 1999;353(9165):1675–1676. doi:10.1016/s0140-6736(99)01346-x
- Prizment AE, Vierkant RA, Smyrk TC, et al. Tumor eosinophil infiltration and improved survival of colorectal cancer patients: Iowa Women's Health Study. Mod Pathol. 2016;29(5):516–527. doi:10.1038/modpathol.2016.42
- Harbaum L, Pollheimer MJ, Kornprat P, Lindtner RA, Bokemeyer C, Langner C. Peritumoral eosinophils predict recurrence in colorectal cancer. Mod Pathol. 2015;28(3):403-13.
- Journal of Clinical Oncology. 29:2011. "Peripheral blood eosinophil counts and risk of colorectal cancer mortality in a large general population-based cohort study."
- Modern Pathology. Sep 12, 2014. "Peritumoral eosinophils predict recurrence in colorectal cancer."
Brown is a writer with expertise in many topics, including law, health, fitness, travel and outdoor recreation. Brown earned a Bachelor of Science degree in history from Utah State University. He began working as a freelance writer in 2007, and his articles appear on several Demand Studio websites, including eHow.