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Chocolate-Specific IgG, Radioallergosorbent (RAST) Test — Qualitative (Deprecated)

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

A deprecated qualitative test for chocolate-specific IgG using an older RAST-type allergy-testing method. It is not a standard test for diagnosing chocolate allergy.

Quick summary

["A positive result shows IgG directed against chocolate, but it does not by itself mean you have a chocolate allergy."]

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

Key facts at a glance

LOINC
21196-1
Short code
Deprecated Chocolate IgG RAST Ql
Synonyms
Deprecated Chocolate 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 is a qualitative test that looks for IgG antibodies directed against chocolate in a blood sample. RAST refers to an older radioallergosorbent testing method, and this test entry is now deprecated.

Why might I need this test?

It may have been used to assess an immune response to chocolate or to help evaluate a suspected food-related reaction. Because current allergy tests are more specific, a clinician may recommend a different test.

How is the test performed?

A blood sample is combined with a chocolate preparation, and the laboratory evaluates whether chocolate-specific antibodies bind to it. The result is reported as detectable or not detectable rather than as a measured concentration.

How do I prepare for the test?

Follow your clinician's instructions. This blood test usually does not require fasting, but your clinician may give specific preparation guidance. Tell the clinician about any history of food reactions, symptoms, or diagnosed allergies.

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

Chocolate IgG RAST

Frequently asked questions

Does a positive result mean I am allergic to chocolate?
No. This test detects IgG, which can reflect prior exposure and is not the same as the IgE response used to diagnose many food allergies. Your clinician should interpret the result alongside your symptoms and medical history.
What should I do if I have symptoms after eating chocolate?
Discuss the reactions with a healthcare professional, especially if you have hives, swelling, wheezing, or difficulty breathing. Seek emergency care for severe breathing difficulty, throat swelling, faintness, or a rapidly worsening reaction.
Is there a newer alternative to this test?
Yes. Depending on the clinical situation, a clinician may recommend current allergy testing, such as skin-prick testing or a food-specific IgE blood test, along with a careful assessment of 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