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Chili Pepper-Specific IgG Antibody, Qualitative — Radioallergosorbent Test (RAST; Deprecated)

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

A qualitative blood test for antibodies against chili pepper. This deprecated RAST-based test is not a standard way to diagnose food allergy.

Quick summary

["This obsolete test may show chili pepper exposure or sensitization, but a result should not be used by itself to diagnose allergy."]

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

Key facts at a glance

LOINC
21451-0
Short code
Deprecated Chili Pepper IgG RAST Ql
Synonyms
Deprecated Chili Pepper 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 test looks for chili pepper-specific IgG antibodies in a blood sample. RAST stands for radioallergosorbent test, and this version of the test is deprecated and is no longer routinely recommended.

Why might I need this test?

It may appear in older records or have been ordered to evaluate a suspected food-related reaction. However, food-specific IgG results generally do not distinguish an allergy from tolerance or a prior immune response.

How is the test performed?

The laboratory uses the RAST method to detect IgG antibodies that react with chili pepper components. The result is reported as positive or negative, or sometimes as a qualitative reaction level.

How do I prepare for the test?

No special preparation is usually needed for a routine blood draw. Tell your clinician about food allergies, recent reactions, and any immunosuppressive medicines, because these factors may affect interpretation.

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

Chili pepper IgG antibody test (deprecated)

Frequently asked questions

Does a positive result mean I am allergic to chili pepper?
No. Chili pepper-specific IgG can occur in people who tolerate the food and does not confirm an allergy. Symptoms and other appropriate clinical tests are more useful for diagnosis.
Why is this test called deprecated?
It is an older testing approach that is no longer routinely recommended for diagnosing food allergy. It may still appear in historical records or legacy laboratory catalogs.
What should I do if I have symptoms after eating chili pepper?
Discuss the reaction with your clinician or allergist, especially if it included hives, swelling, breathing difficulty, or vomiting. Seek emergency care for severe breathing problems, throat swelling, faintness, or a rapidly developing widespread reaction.
  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