Skip to content

Whole Egg-Specific IgE, Qualitative (RAST)

Published: August 9, 2026Updated: August 17, 2026

A blood test that detects IgE antibodies to egg proteins to help evaluate a suspected egg allergy or food allergy.

Quick summary

["A positive result suggests an immune response to egg, but it must be interpreted with symptoms and other allergy evaluation findings."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
15690-1
Short code
Deprecated Whole Egg IgE RAST Ql
Synonyms
Deprecated Whole Egg IgE 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 is an allergen-specific IgE blood test for egg. It measures antibodies your immune system may make in response to egg proteins; the older term RAST is sometimes used for this type of testing.

Why might I need this test?

This test may be used to help evaluate suspected egg allergy, particularly when symptoms occur after eating egg or when allergy testing is needed without deliberately exposing you to the suspected allergen.

How is the test performed?

A blood sample is collected and analyzed in a laboratory for IgE antibodies directed against egg proteins. You do not need to eat egg before the test.

How do I prepare for the test?

Fasting is usually not required. Tell your healthcare professional if you are taking an anti-IgE medicine, because it may reduce test results, and discuss any recent allergy testing or allergen immunotherapy.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Whole Egg IgE

Frequently asked questions

Does a positive result mean I am allergic to egg?
It shows that your immune system has produced IgE antibodies to egg proteins. Your clinician will interpret this with your symptoms and other findings to determine whether egg allergy is likely.
Do I need to eat egg before this test?
No. The test is performed using a blood sample and does not require deliberate exposure to egg.
Can I have egg allergy even if this test is negative?
Yes. Some allergic reactions may involve immune mechanisms other than IgE, so a negative result does not always rule out egg allergy. Your clinician may recommend additional evaluation based on your symptoms.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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