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Serum or plasma concentration of igE (Immunoglobulin E) by immunoassay

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

This test measures the amount of Immunoglobulin E (IgE), a type of antibody that your body produces in response to allergens or infections.

Quick summary

["IgE helps identify allergic reactions or immune responses."]

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

Key facts at a glance

LOINC
102576-6
Short code
Rose Hip IgE RAST
Synonyms
Rose Hip IgE RAST
Category
chemistry
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
Method
rast
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 Does IgE Measure?

IgE is part of your immune system’s defense against certain substances like pollen, dust mites, or insect bites. High levels may suggest allergies, asthma, or other immune-related conditions. Low levels are less commonly evaluated but could indicate certain immune deficiencies.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms like sneezing, itching, skin rashes, or breathing difficulties that suggest allergies. It can also help diagnose conditions like allergic asthma, atopic dermatitis, or parasitic infections.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab for analysis using an immunoassay method to detect IgE antibodies.

What Do Results Mean?

Results are not always interpreted alone but are often compared to your symptoms and medical history. Elevated IgE levels may indicate an allergic reaction or immune response, while normal or low levels may not provide a definitive diagnosis.

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.

Clinical Significance: IgE plays a key role in allergic reactions and allergic diseases. High IgE levels can signal an overactive immune response to allergens, while certain conditions like parasitic infections may also raise IgE. Doctors use these results to guide treatment plans, such as allergy testing or managing symptoms.

Short name

IgE Level

Frequently asked questions

What causes elevated IgE levels?
Elevated IgE levels are most commonly linked to allergies (e.g., to pollen, pet dander, or food), asthma, or atopic dermatitis. They can also occur with certain parasitic infections or autoimmune conditions, though these are less common. Your doctor will consider your symptoms and medical history to determine the cause.
What if my IgE levels are normal but I still have allergy symptoms?
Normal IgE levels don’t rule out allergies entirely. Other tests, like skin prick tests or specific IgE antibody tests, may be needed to identify triggers. Your doctor may also recommend monitoring symptoms or other diagnostic tests to find the root cause.
Can IgE levels change over time?
Yes, IgE levels can fluctuate based on exposure to allergens, underlying health conditions, or treatments like allergy medications or immunotherapy. If your levels change, it may reflect improvements or worsening of your condition, so follow-up testing may be recommended.
  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