Hazelnut-Specific IgE, Qualitative (RAST; Deprecated Test)
A blood test that checks for IgE antibodies to hazelnut. It is a legacy allergy test and has largely been replaced by other allergen-specific antibody methods.
["A positive result suggests sensitization to hazelnut but does not by itself confirm a clinical allergy."]
Key facts at a glance
- LOINC
- 35731-9
- Short code
- Deprecated Hazelnut IgG RAST Ql
- Synonyms
- Deprecated Hazelnut IgG RAST Ql
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This legacy blood test, commonly described as a RAST test, looks for hazelnut-specific IgE antibodies. IgE is one type of immune response that can occur when a person's immune system reacts to a food allergen. The compressed name is marked as deprecated, so the test may no longer be routinely offered.
Why might I need this test?
It may have been used to help evaluate a suspected hazelnut allergy, especially when a person has symptoms after eating hazelnuts or products containing them. Results are most useful together with the person's symptoms, exposure history, and other allergy evaluations.
How is the test performed?
A blood sample is collected and analyzed in a laboratory for antibodies directed against hazelnut allergens. The original RAST method used a radioactive reagent, but many laboratories now use nonradioactive testing methods for allergen-specific IgE.
How do I prepare for the test?
No special preparation is usually required for this blood test. If your clinician is evaluating a food allergy, continue avoiding the suspected food unless your clinician gives different instructions. Tell the laboratory if you are taking medicines that could affect the results or recently had immunotherapy.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result indicates that hazelnut-specific IgE is present, which is consistent with sensitization to hazelnut. It does not always mean that eating hazelnut will cause a reaction, and some people have positive results without symptoms. If you have had hives, swelling, wheezing, vomiting, or other reactions after eating hazelnuts, discuss the result promptly with a healthcare professional.
Short name
Hazelnut-Specific IgE
Frequently asked questions
Does a positive result mean I have a hazelnut allergy?
Can this test be used to diagnose a food allergy?
Why is the test listed as deprecated?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy