Regional Allergen Mix 1-Specific IgE, Serum — Radioallergosorbent Test (RAST)
A blood test that screens for IgE antibodies to a group of common allergens found in a specific geographic region.
["A positive result suggests allergy sensitization, but symptoms and medical history are needed to determine whether the allergens cause your symptoms."]
Key facts at a glance
- LOINC
- 82102-5
- Short code
- Region Allerg Mix1 IgE RAST
- Synonyms
- Region Allerg Mix1 IgE RAST
- 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
- Method
- multidisk
- 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 measures allergen-specific IgE antibodies in a blood sample using a radioallergosorbent test, or RAST. It screens for immune sensitization to allergens included in a regional mixture, whose contents may vary by the laboratory and geographic area.
Why might I need this test?
It may be used to help identify possible triggers of allergic rhinitis, wheezing, hives, or other allergic symptoms when the cause is unclear. The panel can be a useful starting point before more specific allergy testing is considered.
How is the test performed?
A blood sample is collected and tested in a laboratory for IgE antibodies against the allergens in the regional mixture. The laboratory may report each allergen separately or provide a combined result, depending on the test used.
How do I prepare for the test?
Fasting is usually not required. Tell your healthcare professional about your allergies, current symptoms, allergy treatments, and any recent immunotherapy, because these details may affect how the results are interpreted.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detectable IgE to one or more allergens indicates sensitization and may help explain symptoms related to exposure. However, a positive result does not by itself prove that the allergens cause your symptoms, and test strength does not reliably predict reaction severity. Results should be interpreted with your medical history and, when needed, additional allergy testing.
Short name
Regional Allergen Mix 1 IgE (RAST)
Frequently asked questions
Does a positive RAST mean I am allergic?
What allergens are included in the regional mix?
Should I stop taking allergy medicine before the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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