Immunoglobulin E (IgE): Normal Ranges & What High Levels Mean

Updated in December 2023

Immunoglobulin E (IgE) is a protein that is present in low levels in the blood. It is normally found on the surface of some blood cells, mainly basophils and mastocytes.

High levels of basophils and mastocytes will usually lead to high levels of IgE. This can happen as a result of an allergic reaction, however high IgE, basophil and mastocytes levels can also occur with parasitic infections and chronic diseases, like asthma.

IgE levels are evaluated through a blood test. Fasting is not required for this test.

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Common uses

The doctor may order IgE levels in the following situations:

  • To investigate frequent allergies
  • To investigate for a parasitic infection
  • To investigate for Allergic bronchopulmonary aspergillosis (ABPA), a condition caused by fungus that compromises the respiratory system

Immunoglobulin E blood tests are one of the main tests ordered to diagnose allergies. An increased IgE level, however, should not be the only parameter used to confirm a diagnosis. The doctor will usually also order specific allergy testing.

In addition, while this test is sensitive to changes in levels, it is not specific and does not offer information about the type of allergy present. The doctor will additionally order specific IgE testing, which looks at the presence of IgE proteins for specific allergens, like nuts or dust mites.

Normal ranges

Normal immunoglobulin E levels vary with the person‘s age and the laboratory’s standard reference values. Typically, normal IgE levels are as follows:


Reference range

0 to 1 years old

Up to 15 kU/ L

1 to 3 years old

Up to kU/ L

4 to 9 years old

Up to kU/ L

10 to 11 years old

Up to 123 kU/ L

11 to 14 years old

Up to 240 kU/ L

Over 15 years old

Up to 160 kU/ L

What do high IgE levels mean?

The main cause of elevated IgE leels are allergies, however there are other conditions that can also trigger an increase in IgE levels, such as:

  • Allergic rhinitis
  • Atopic eczema
  • Parasitic infections
  • Inflammatory diseases, like Kawasaki’s disease
  • Myeloma
  • ABPA
  • Asthma

IgE levels can also become elevated with inflammatory bowel syndromes, chronic infections and liver disease.

Hyper IgE syndrome

Hyper IgE syndrome (HIES), also known as Job‘s syndrome, is a type of primary immunodeficiency disorder characterized by abnormally high IgE levels and high eosinophil levels. This abnormality can also present with eczema, bacterial skin abscesses, pulmonary abscessed, joint abscesses, decreased bone density and an increased risk for fractures.

It is important for the family doctor, rheumatologist or allergy specialist to assess the possibility of this disease and to start treatment as appropriate. Treatment may involve antibiotics, antihistamines and topical ointments for the skin.

How the test is done

The IgE blood test does not require any fasting from the patient. A blood sample is collected and sent to the alb for analysis. Results are usually communicated less than 2 days later, with the report outlining the current IgE level as well as the normal reference range.

It is important for results to be interpreted by the ordering physician, along with other test results. The total IgE test result will not offer information about the specific type of allergy, which is why doctors will usually order complimentary testing.