LAB TEST
Eosinophil count - absolute
An absolute eosinophil count is a blood test that measures the number of one type 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 an 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…
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)…
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. This test may help diagnose: Acute hypereosinophilic syndrome (a rare, but sometimes fatal leukemia-like condition) An allergic reaction (can…
Normal Results
Normal eosinophil count is less than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results. The example above shows the common measurements for results of these tests. Some laboratories use…
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: Adrenal gland deficiency Allergic disease, including hay fever Asthma Autoimmune diseases Eczema Fungal infections Hypereosinophilic syndrome Leukemia and other blood disorders Lymphoma…
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
Khoury P, Akuthota P, Weller PF, Klion AD. Eosinophilia and eosinophil-related disorders. In: Burks AW, Holgate ST, O' Hehir RE, Broide DH, et al. eds. Middleton's Allergy: Principles and Practice . 9th ed. Philadelphia, PA: Elsevier; 2020:chap 73. Klion AD. Eosinophilic syndromes. In: Goldman L, Schafer AI, eds.…
This is a summary. Read the full article at www.ucsfbenioffchildrens.org (reviewed 25/01/2023).
This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.