Also Known As
Quantitative IgE
Formal Name
Immunoglobulin E
This article was last reviewed on
This article waslast modified on November 5, 2017.
At a Glance
Why Get Tested?

To screen for an allergic disease; sometimes to screen for a parasitic infection

When To Get Tested?

When you have periodic or persistent skin, lung, or digestive symptoms that suggest allergies; when a healthcare practitioner suspects a parasitic infection

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

None

You may be able to find your test results on your laboratory's website or patient portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab's website or portal, or contact your healthcare practitioner in order to obtain your test results.

Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

What is being tested?

Immunoglobulin E (IgE) is an antibody that is produced by the body’s immune system in response to a perceived threat. It is one of five classes of immunoglobulins (A, G, M, D, and E) and is normally present in the blood in very small amounts. This test measures the amount of IgE in the blood.

Immunoglobulins are proteins that play a key role in the body's immune system. They are produced by specific immune cells called plasma cells. Immunoglobulins are produced in response to bacteria, viruses, and other microorganisms as well as substances that are recognized as "non-self" or present harmful antigens to the immune system.

Immunoglobulin E is associated with allergic responses, including asthma, and to a lesser degree with immunity to parasites. With allergies, the body overreacts to one or more substances in the environment called allergens that do not typically cause a response in other people. Someone may develop an allergy when that person is exposed to an allergen, such as plant pollen, peanuts, eggs, strawberries, bee venom, and hundreds of other potential substances.

During an initial exposure, also called sensitization, an allergic person produces an IgE specifically directed against that allergen. IgE binds to specialized white blood cells, resulting in the release of a number of substances, including histamine. In allergic/asthmatic people, this can cause constriction of the bronchi in the lungs. These substances are also responsible for the running nose, itchy eyes, and skin itching that occur in people with allergies.

Each time an allergic person is exposed to a specific allergen(s) after the initial exposure, IgE is rapidly produced, increasing to levels that trigger an allergic reaction. The severity of the reaction and symptoms associated with each episode can range from a localized reddening and itching of the skin, to respiratory distress, to vomiting and diarrhea, and in some cases to life-threatening anaphylaxis. Severity will vary from person to person, can vary from episode to episode, and may worsen over time.

The total IgE test measures the overall quantity of immunoglobulin E in the blood, not the amount of a specific type. It can be used to detect an allergic response in the body rather than a specific allergy. This test may compliment the information provided by allergy tests that detect allergen-specific IgE.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

Accordion Title
Common Questions
  • How is it used?

    The total IgE test may be used to help screen for and detect allergic diseases. It measures the overall quantity of immunoglobulin E in the blood. It may be ordered by itself, before, or along with allergen-specific IgE tests, depending upon whether or not a person or healthcare practitioner has identified potential substances to which the person may be allergic.

    Immunoglobulin E (IgE) is an antibody that is produced by the body's immune system in response to a perceived threat. It is one of five classes of immunoglobulins and is normally present in the blood in very small amounts. IgE is associated with allergic responses, including asthma, and to a lesser degree with immunity to parasites. (For more, see the "What is being tested?" section.)

    IgE can be increased with parasitic infections, so a total IgE test is sometimes used as a screening test if a parasitic infection is suspected.

  • When is it ordered?

    A total IgE test may be ordered when a person has periodic or persistent symptoms that may be due to an allergic reaction, especially when the potential allergen is unknown. Symptoms may include those that suggest skin, respiratory, and/or digestive involvement, such as:

    • Periodic or persistent itching
    • Hives
    • Itchy eyes
    • Eczema
    • Nausea, vomiting, persistent diarrhea
    • Sneezing, coughing, congestion
    • Difficulty breathing
    • Asthma symptoms: wheezing, breathlessness, coughing, tightness in the chest

    Sometimes an IgE may be ordered as a screening test when a person has persistent diarrhea that may be due to a parasitic infection. In addition, a complete blood count (CBC) with white blood cell differential may be ordered to determine if the number of eosinophils is increased.

  • What does the test result mean?

    An increased total IgE level indicates that it is likely that a person has one or more allergies. Allergen-specific IgE levels will increase after an exposure and then decline over time, thus affecting the total IgE level. If a person is allergic to a seasonal substance, such as pollen, then both the specific IgE and total IgE would be expected to increase during the time of year when the allergen is present. If someone has one or more food allergies, then the total IgE level would mirror exposures to these foods. If someone is allergic to something that they are constantly around, such as mold in a house or cat dander, then the total IgE level may be persistently increased.

    An elevated level of total IgE indicates an allergic process is likely present, but it will not indicate what a person is allergic to. In general, the greater the number of things a person is allergic to, the higher the total IgE level may be. An IgE elevation can also indicate the presence of a parasitic infection but cannot be used to determine the type of infection.

    A normal IgE level makes it less likely that a person has allergies but does not rule them out due to the length of time between exposures. In between exposures, a person's IgE level may drop.

    Sometimes an individual has a condition that affects the immune system and will not produce normal amounts of immunoglobulins. In this case, a person could have an allergy that is not reflected by the total IgE test result.

  • Is there anything else I should know?

    In order to identify specific allergies, a healthcare practitioner must order tests that detect allergen-specific IgE. If a person is suspected of having an allergy to cats, then a cat dander IgE test must be ordered. If the person actually has an allergy to dogs, it will not be detected with this test. For this reason, healthcare practitioners may screen with a total IgE test, then run panels of substance-specific IgE tests. These panels may include a range of common allergens or similar types of allergens, such as various grasses, pollen, molds, pet dander, and/or foods.

    A person's symptoms during an allergic episode do not necessarily correlate with that person's total IgE level.

    Infrequently, an IgE test may be ordered to help diagnose a very rare inherited disease called hyperimmunoglobulin E syndrome (Job syndrome). People with this disease often have significantly higher than normal IgE levels and may have eczema, recurrent sinus and lung infections, bone defects, and severe skin infections. A greatly increased IgE concentration may indicate that an individual has inherited this condition. Additional testing can be performed to detect a mutation in the STAT3 gene that has been associated with this disorder.

    Rarely, the IgE test is used to help diagnose and monitor multiple myeloma that produces monoclonal IgE.

  • Is there anything I can do to lower my IgE level?

    Other than limiting your exposure to things that you are allergic to, no. The total IgE concentration is not influenced by lifestyle changes, and lowering it would not have an effect on the number or type of allergies that you have.

  • Can the total IgE test be performed in my doctor’s office?

    In some cases, it might be available in an office or clinic, such as with a healthcare provider who specializes in allergies, but in most cases it will be performed in a laboratory.

  • How effective is the skin test for allergies?

    The skin of the arm or back is pricked with a needle containing a specific allergen, causing a red swelling when positive. It is very specific but requires multiple skin pricks for each type of allergen to be tested and must be interpreted by a trained specialist.

View Sources

Sources Used in Current Review

(© 1995–2016). Immunoglobulin E (IgE), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/8159. Accessed 4/06/16.

Durani, Y. (2014 September Reviewed). Immunoglobulin E. KidsHealth from Nemours. [On-line information]. Available online at http://kidshealth.org/en/parents/test-immunoglobulin-e.html. Accessed 4/06/16.

Morris, M. (2016 March 25 Updated). Asthma. Medscape Drugs and Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/296301-overview. Accessed 4/06/16.

Schwartz, R. and Tarlow, M. (2015 August 31 Updated). Dermatologic Manifestations of Job Syndrome. Medscape Drugs and Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/1050852-overview. Accessed 4/06/16.

Delgado, J. et. al. (2016 April Updated). Immunoglobulin Disorders. ARUP Consult [On-line information]. Available online at https://arupconsult.com/content/immunoglobulin-disorders?tab=tab_item-0. Accessed 4/06/16.

(2015 July 1 Updated). Hyper-Immunoglobulin E Syndrome (HIES) or Job's Syndrome. National Institute of Allergy and Infectious Diseases [On-line information]. Available online at http://www.niaid.nih.gov/topics/jobssyndrome/Pages/default.aspx. Accessed 4/06/16.

Sources Used in Previous Reviews

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby’s Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 581-584.

Daller, J. (Updated 2011 August 1). Hyperimmunoglobulin E syndrome. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/001311.htm. Accessed January 2012.

Mayo Clinic Staff (2011 July 28). Primary Immunodeficiency. Mayo Clinic [On-line information]. Available online at http://www.mayoclinic.com/health/primary-immunodeficiency/DS01006. Accessed January 2012.

Jyonouchi, H. (Updated 2011 August 2). Hyperimmunoglobulinemia E (Job) Syndrome. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/886988-overview#showall. Accessed January 2012.

(© 1995-2012). Test ID: IGE Immunoglobulin E (IgE), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/8159. Accessed January 2012.

Hill, H. and Wittwer, C. (Updated 2011 April). Neutrophil Disorders. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/NeutrophilDisorders.html?client_ID=LTD. Accessed January 2012.

Delgado, J. et. al. (Updated 2011 January). Immunoglobulin Disorders. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/ImmunoglobulinDisorders.html?client_ID=LTD#tabs=0. Accessed January 2012.

Dowshen, S. (Reviewed 2011 February). Blood Test: Immunoglobulin E (IgE). KidsHealth from Nemours [On-line information]. Available online at http://kidshealth.org/parent/system/medical/test_immunoglobulin_e.html. Accessed January 2012.

Lowry, F. (2010 November 18). Age-Related IgE Levels on the Rise in the United States. Medscape Medical News from the: American College of Allergy, Asthma & Immunology (ACAAI) 2010 Annual Scientific Meeting [On-line information]. Available online at http://www.medscape.com/viewarticle/732797. Accessed January 2012.

(Updated 2011 August). Handout on Health: Atopic Dermatitis. National Institute of Arthritis and Musculoskeletal and Skin Diseases [On-line information]. Available online at http://www.niams.nih.gov/Health_Info/Atopic_Dermatitis/default.asp. Accessed January 2012.

Heimall, J. et. al. (Updated 2010 August 4). Job Syndrome. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/1547969-overview. Accessed January 2012.

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