Immunoglobulin E (IgE) Blood Test

Also called: Total IgE Test

What Is an Immunoglobulin E Blood Test?

An immunoglobulin E (IgE) test measures the level of IgE, a type of antibody. Antibodies (also called immunoglobulins) are proteins the immune system makes to recognize and get rid of germs it thinks are harmful.

Why Are IgE Tests Done?

Doctors may order an IgE test if a child has signs of a possible:

• Allergy. Symptoms may include hives, trouble breathing, a scratchy throat, itchy eyes, or swelling of the face or throat.
• Immune system problem, like eczema, lupus, or chronic hives. Symptoms may include itchy skin, rashes, or joint pain.
• Infection with a parasite (an organism that needs to live on or in a person, animal, or plant to survive). Symptoms may include diarrhea , blood or mucus in the poop, belly pain, nausea, headaches, or fever.

Top Things to Know

• The immunoglobulin E (IgE) test blood test checks how much of an antibody called IgE is in the blood.
• This test may be done if kids have symptoms of allergies, an immune system condition, or a parasitic infection.
• Kids might need to stop taking certain medicines or not eat or drink before the blood test.
• Your doctor can explain what it means if the IgE level is high or low.

How Can I Help My Child Prepare for a Blood Test?

To help kids get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is nervous about it, work together on ways to stay calm. Deep breathing or even imagining being in a peaceful place that makes your child feel safe and relaxed can help.

What Do IgE Test Results Mean?

Your doctor will explain what the results of the IgE test mean for your child. “Normal” levels vary based on things like age and gender.

The blood usually has small amounts of IgE antibodies. Higher amounts can be a sign that the body overreacts to allergens (the things that can bring on allergic reactions, like pollen or a type of food).

IgE levels can also be high when the body is fighting an infection from a parasite and from some immune system conditions.

Low amounts of IgE usually aren’t a problem. It often means the body isn’t strongly reacting to allergens.

What Else Should I Know?

When doctors check for allergies, kids may have an allergen-specific IgE blood test. By using this and a total IgE test, doctors can see how specific IgE levels compare to the total IgE level. Kids often have allergy skin tests too.

If you have questions about the IgE test or what the results mean, talk with your doctor.