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In person

Hazelnut Allergy (IgE) with Component Reflex

Hazelnut IgE, with components added if it is positive.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
3 to 5 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

This test measures IgE antibodies to hazelnut. If the result is positive, the lab runs a follow-up test on the same sample for four hazelnut proteins, which can help tell birch-pollen cross-reactions from hazelnut-specific sensitization. A positive result shows sensitization.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

For adults who have had a reaction to hazelnut or other tree nuts and want to check for sensitization, with more detail if positive, before seeing an allergist.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your results show whether your blood has IgE to hazelnut and, if so, to which hazelnut proteins. An allergist reads the pattern with your symptoms and history.

Hazelnut-specific IgE (f17)
Specific IgE is an antibody the immune system can make against a single food. This marker measures IgE that recognizes hazelnut, a tree nut. A level above the lab’s reference range shows sensitization, which an allergist reads with your history.
Why it’s measured: The first test in this reflex; components are added if it is positive.
Cor a 1-specific IgE (f428)
Cor a 1 is a hazelnut protein similar to a protein in birch pollen. IgE to it can come from birch pollen sensitization that cross-reacts with hazelnut. On its own it does not tell you how you would react to hazelnut or whether you can eat it, so an allergist reads it with your history.
Why it’s measured: Added when hazelnut IgE is positive, to help an allergist read the result.
Cor a 8-specific IgE (f425)
Cor a 8 is a lipid transfer protein, part of a plant protein family found in many fruits, nuts, and vegetables. IgE to it can reflect sensitization shared across plant foods. On its own it does not tell you whether you can eat hazelnut, so an allergist reads it with your history.
Why it’s measured: Added when hazelnut IgE is positive, to help an allergist read the result.
Cor a 9-specific IgE (f440)
Cor a 9 is a storage protein in hazelnut. Component tests like this one give an allergist more specific information about a positive hazelnut result. No single component result tells you how you would react or whether you can eat hazelnut, so an allergist reads it with your history.
Why it’s measured: Added when hazelnut IgE is positive, to help an allergist read the result.
Cor a 14-specific IgE (f439)
Cor a 14 is a storage protein in hazelnut. Component tests like this one give an allergist more specific information about a positive hazelnut result. No single component result tells you how you would react or whether you can eat hazelnut, so an allergist reads it with your history.
Why it’s measured: Added when hazelnut IgE is positive, to help an allergist read the result.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 3 to 5 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

Your result is reported as an IgE level in kU/L and compared with the lab’s reference range. A level above the range shows sensitization.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

Decisions about eating hazelnut belong with an allergist or other healthcare provider, who reads these results with your history.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

Get emergency care. If you have trouble breathing, swelling of the face or throat, or you feel faint or pass out after eating any food, call 911 right away. If you have a prescribed epinephrine auto-⁠injector, use it as directed. This blood test is not for urgent reactions.

After a serious reaction, an allergist can talk with you about what happened and which tests make sense.

If the first result is positive, the lab runs a follow-⁠up test on the same sample that looks at IgE to individual hazelnut proteins.

If the first result is not positive, no follow-⁠up test is run. Either way, an allergist reads the results with your history.

A whole-⁠hazelnut IgE result shows sensitization to hazelnut as a whole. Component testing measures IgE to four individual hazelnut proteins, which gives an allergist more specific information, such as whether a result may come from a birch pollen cross-⁠reaction.

No component result on its own tells you how you would react, and a pattern that looks like a cross-⁠reaction does not mean you can eat hazelnut. Decisions about eating hazelnut belong with an allergist.

Not on its own. A positive result means your immune system has made IgE to hazelnut, which is called sensitization. Many people who are sensitized have no symptoms when they are exposed.

A diagnosis of allergy is made by a healthcare provider who looks at your symptoms and history along with results like this one. A negative result also does not by itself mean you are not allergic.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.