A patient seated in the chair before a blood draw
In person

Hazelnut Component Panel

IgE to 4 individual hazelnut proteins, from one blood draw.

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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 panel measures IgE antibodies to four individual hazelnut proteins, which can help an allergist tell birch-pollen cross-reactions from hazelnut-specific sensitization. It is usually a follow-up to a positive hazelnut IgE result. A positive result shows sensitization, not necessarily an allergy.

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

Who should take this test?

For adults who have had a positive hazelnut IgE result and are working with an allergist who wants more detail about which hazelnut proteins are involved.

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 which hazelnut proteins, if any, your blood has IgE to. An allergist reads that pattern with your whole hazelnut result and your history.

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: Helps an allergist see which hazelnut proteins your IgE recognizes.
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: Helps an allergist see which hazelnut proteins your IgE recognizes.
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: Helps an allergist see which hazelnut proteins your IgE recognizes.
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: Helps an allergist see which hazelnut proteins your IgE recognizes.

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

Each allergen 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, who reads these results with your whole hazelnut result and 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.

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.

This test is usually a follow-⁠up to a positive hazelnut IgE result. Whole-⁠food IgE tests can be positive in people who do not react to the food, and component tests give an allergist more specific information.

If you have not had a hazelnut IgE test, the version with a component reflex checks hazelnut IgE first and adds these tests on the same sample if it is positive.

No. This test is not for urgent reactions. If you have trouble breathing, swelling of the face or throat, or you faint after eating any food, call 911 or get emergency care right away. If you have a prescribed epinephrine auto-⁠injector, use it as directed.

Once a reaction has passed, an allergist or other healthcare provider can help you decide on next steps, including whether testing fits.

No. Sensitization means your body has made IgE to hazelnut. An allergy means that exposure causes symptoms. Many people are sensitized without having symptoms, so a positive result alone does not mean you are allergic.

A negative result does not clear an allergy either. An allergist or other healthcare provider reads your result with your history.

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.