Skip to content

Cow Milk-Specific IgE, Radioallergosorbent (RAST) Test, Qualitative (Deprecated)

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

A qualitative test for IgE antibodies to cow's milk, used to help evaluate possible milk allergy. This legacy test has been deprecated.

Quick summary

["A positive result suggests immune sensitization to cow's milk but must be interpreted with allergy symptoms and medical history."]

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

Key facts at a glance

LOINC
25383-1
Short code
Deprecated Cow Milk IgE RAST Ql
Synonyms
Deprecated Cow Milk 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 looks for IgE antibodies directed against cow's milk proteins. It is an older qualitative form of food-specific IgE testing, sometimes called a RAST test, and is now deprecated.

Why might I need this test?

A clinician may use it when a person has symptoms suggesting an immediate cow's-milk allergy, such as hives, swelling, wheezing, vomiting, or other reactions after exposure. The result is considered together with symptoms, exposure history, and sometimes other allergy tests.

How is the test performed?

A submitted sample is analyzed for antibodies that bind to cow's-milk proteins. The qualitative version reports whether cow's-milk-specific IgE is detected rather than providing a measured concentration.

How do I prepare for the test?

There is usually no special preparation for this laboratory test. Tell your clinician about food reactions, recent changes in diet, and medicines such as antihistamines, because these factors may affect how the result is interpreted.

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

Cow milk-specific IgE (RAST), qualitative

Frequently asked questions

Does a positive result mean I am allergic to cow's milk?
It shows that cow's-milk-specific IgE antibodies are present. Your clinician must interpret this with your symptoms and exposure history because sensitization does not always cause a clinical allergy.
Is this the same as a lactose intolerance test?
No. This test evaluates an immune response to milk proteins, whereas lactose intolerance results from difficulty digesting the milk sugar lactose.
Why was this test deprecated?
It is an older qualitative testing method and is no longer the preferred form of food-allergy evaluation. Your clinician may recommend a currently available specific-IgE test or another approach based on your situation.
  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