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Eosinophil count - absolute
Eosinophils; Absolute eosinophil count
An absolute eosinophil count is a blood test that measures the number of white blood cells called eosinophils. Eosinophils become active when you have certain allergic diseases, infections, and other medical conditions.
How the Test is Performed
Most of the time blood is drawn from a vein on the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around your upper arm to make the vein swell with blood.
Next, the provider gently inserts a needle into the vein. The blood collects into an airtight tube attached to the needle. The elastic band is removed from your arm. The needle is then removed and the site is covered to stop bleeding.
In infants or young children, a sharp tool called a lancet may be used to prick the skin. The blood collects in a small glass tube, or onto a slide or test strip. A bandage is put on the spot to stop bleeding.
In the lab, the blood is placed on a microscope slide. A stain is added to the sample. This causes eosinophils to show up as orange-red granules. The technician then counts how many eosinophils are present per 100 cells. The percentage of eosinophils is multiplied by the white blood cell count to give the absolute eosinophil count.
White blood cell count
A WBC count is a blood test to measure the number of white blood cells (WBCs) in the blood. WBCs help fight infections. They are also called leukocy...
How to Prepare for the Test
Most of the time, adults do not need to take special steps before this test. Tell your provider the medicines you are taking, including the ones without a prescription. Some drugs may change the test results.
Medicines that may cause you to have an increase in eosinophils include:
- Amphetamines (appetite suppressants)
- Certain laxatives containing psyllium
- Certain antibiotics
- Interferon
- Tranquilizers
How the Test will Feel
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
Why the Test is Performed
You will have this test to see if you have abnormal results from a blood differential test. This test may also be done if the provider thinks you may have a specific disease.
Blood differential test.
A WBC count is a blood test to measure the number of white blood cells (WBCs) in the blood. WBCs help fight infections. They are also called leukocy...
This test may help diagnose:
- Acute hypereosinophilic syndrome (a rare, but sometimes fatal leukemia-like condition)
-
An
allergic reaction
(can also reveal how severe the reaction is)
Allergic reaction
Allergic reactions are sensitivities to substances called allergens that come into contact with the skin, nose, eyes, respiratory tract, and gastroin...
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Early stages of
Cushing's disease
Cushing's disease
Cushing disease is a condition in which the pituitary gland releases too much adrenocorticotropic hormone (ACTH). The pituitary gland is an organ of...
ImageRead Article Now Book Mark Article - Infection by a parasite
Normal Results
Less than 500 cells per microliter (cells/mcL) or 0.50 x 10^9/L.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The example above shows the common measurements for results of these tests. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
A high number of eosinophils (eosinophilia) are often linked to a variety of disorders. A high eosinophil count may be due to:
- Allergic disease
- Parasite infection, such as worms
- Certain fungus infections
-
Asthma
Asthma
Asthma is a disease that causes the airways of the lungs to swell and narrow. It leads to wheezing, shortness of breath, chest tightness, and coughi...
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Autoimmune diseases
Autoimmune diseases
An autoimmune disorder occurs when the body's immune system attacks and destroys healthy body tissue by mistake. There are more than 80 types of aut...
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Eczema
Eczema
Atopic dermatitis is a long-term (chronic) skin disorder that involves scaly and itchy rashes. It is a type of eczema. Other forms of eczema include...
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Hay fever
Hay fever
Allergic rhinitis is a diagnosis associated with a group of symptoms affecting the nose. These symptoms occur when you breathe in something you are ...
ImageRead Article Now Book Mark Article - Leukemia and other blood disorders
A lower-than-normal eosinophil count may be due to:
- Alcohol intoxication
- Overproduction of certain steroids in the body (such as cortisol)
Risks
Risks from having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Considerations
The eosinophil count is used to help confirm a diagnosis. The test cannot tell if the higher number of cells is caused by allergy or parasite infection.
References
Hutchinson RE, Schexineider KI. Leukocyteic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 33.
Roberts DJ. Hermatologic aspects of parasitic diseases. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 160.
Review Date: 1/20/2015
Reviewed By: Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
