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False Ragweed-Specific IgE, Qualitative

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

A qualitative blood test that detects IgE antibodies directed against false ragweed pollen, helping assess possible allergic sensitization.

Quick summary

["A positive result suggests your immune system reacts to false ragweed pollen, but it must be interpreted alongside your symptoms and exposure history."]

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

Key facts at a glance

LOINC
15977-2
Short code
Deprecated False ragweed IgE RAST Ql
Synonyms
Deprecated False ragweed 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 test checks a blood sample for IgE antibodies to false ragweed pollen. It is reported qualitatively as positive or negative rather than as a measured concentration.

Why might I need this test?

It may be ordered if you have sneezing, congestion, itchy or watery eyes, wheezing, or other symptoms around ragweed. The result helps determine whether false ragweed may be an allergy trigger for you.

How is the test performed?

A blood sample is collected and analyzed for antibodies specific to false ragweed. The laboratory reports whether allergen-specific IgE was detected.

How do I prepare for the test?

No fasting is usually required. Tell your clinician about any allergy medicines or immunosuppressive medicines you use, because these may affect the result; do not stop prescribed medicines without medical advice.

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

False Ragweed IgE

Frequently asked questions

What does a positive false ragweed IgE result mean?
It means that IgE antibodies to false ragweed were detected, indicating an immune-system sensitization. A clinician should determine whether this finding matches your symptoms and possible exposures.
Can I have a ragweed allergy with a negative result?
Yes. A negative test makes false ragweed less likely to explain your symptoms, but some allergies may not be detected by this test. Your clinician may consider other testing based on your history.
Do I need to avoid ragweed if the result is positive?
Discuss exposure reduction and treatment options with your clinician or allergist. Advice may depend on the severity of your symptoms and whether the result fits your medical history.
  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