Allergy Blood Test

What is an allergy blood test?

An allergy blood test is a type of allergy test that works by checking for antibodies called immunoglobulin E (IgE) in your blood. Antibodies are proteins your immune system produces in response to certain substances. If you have an allergy, your body usually produces more IgE in response to that allergen.

Common allergens include:

• Foods
• House dust
• Latex
• Insect bites and stings
• Molds
• Pet dander, urine and saliva
• Pollens
• Some medications (like penicillin)

Are there different types of allergy blood tests?

There are two types of allergy blood tests:

• Total IgE test: Measures the total amount of IgE antibodies in your blood. It doesn’t show what you’re allergic to and it’s not highly sensitive. Many people with subtle allergies may have a normal total IgE level.
• Specific IgE test: Measures the IgE antibodies in your blood in response to one particular allergen. It’s the more sensitive test of the two.

When is an allergy blood test needed?

You may need an allergy blood test if you have:

• Allergic rhinitis (hay fever), which is usually the result of environmental allergies like pollen, pet dander or molds
• Anaphylaxis, which is a severe and sometimes life-threatening allergic reaction to certain foods like peanuts, insect stings or other allergens

Your provider may also order an allergy blood test if you have allergy signs and/or symptoms like:

• Hives
• Itchy, red or watery eyes
• Shortness of breath (dyspnea)
• Skin rash
• Sneezing
• Sore throat (pharyngitis)
• Stuffy, itchy or runny nose
• Swollen lips, tongue, eyes or face
• Wheezing, tightness in your chest or allergic asthma