How do I read my allergy blood test results?
How To Interpret Results
- Values under 0.35 mean unlikely sensitization to the allergen.
- Values between 0.35-0.69 mean doubtful significance.
- Values between 0.70-3.49 mean there is a possibility.
- Values between 3.50-17.49 mean a greater possibility.
- Values between 17.50-49.99 mean very likely.
What do RAST test results mean?
Most labs will report the RAST findings on a scale of 0 to 5 or more. A 0 value suggests a low likelihood of an allergy. Values at the upper end are indicative of a higher likelihood of an allergy. Some labs will not use a scale but will simply report the IgE values in micrograms per milliliter (μg/mL).
How accurate are RAST allergy tests?
A negative RAST is as reliable as a negative SPT in ruling out a true food allergy. However, RAST has a slightly higher false positive rate than SPT, making it less reliable for confirming an allergy. If you have been diagnosed with a true food allergy, RAST can be useful in monitoring IgE values.
How severe is a Class 3 allergy?
Class 3: High level of allergy (3.5 KUA/L – 17.4 KUA/L) indicative of high level sensitization.
What allergies does RAST test for?
RAST is used to confirm what a patient may be allergic to, which can improve treatment of allergic diseases such as asthma and allergic rhinitis, when skin prick tests (the preferred allergy test) is not available or is not suitable.
What is Rist and Rast?
With the Radio-Immuno-Sorbent-Test (RIST) the IgE can be quantitatively determined. Elevated IgE-blood levels are typically found in atopic eczema. With the Radio-Allergo-Sorbent-Test (Rast) the allergen specific IgE can be defined. A conformity with appropriate patchtests can be achieved in 60-80% of the cases.
What does Rast mean in medical terms?
The RAST (Radioallergosorbent test) is a laboratory test performed on blood. It tests for the amount of specific IgE antibodies in the blood which are present if there is a “true” allergic reaction.
Can RAST test wrong?
Additional problems with RAST tests are the cost, and the fact that a very high level of total circulating IgE (e.g., in children with severe atopic eczema) may cause a false-positive result.
How long does it take to get RAST test results?
Reactions to a skin test typically develop within 15 minutes, whereas it can take between a few days and 2 weeks to get the results of a RAST test. Accuracy. Skin tests may be more sensitive than blood tests, though both methods are considered accurate for diagnosing allergies.
What does Rast class mean?
Specific IgE-fractions can be determined in the blood serum by Radio-Allergo-Sorbent-Test (RAST). The positive tests are arranged into four groups, the so called RAST-classes, of which class 1 represents the lowest, class 4 the highest content of specific IgE.
How long for results on RAST test?
How Long Can I Get my RAST Blood Test Results? It takes approximately 1-2 weeks for the results to be ready after laboratory processing.
How long do RAST results take?
The preferred method that our office uses for allergy testing is immunoCAP or RAST. RAST and immunoCAP testing is performed by drawing your blood which is than sent out for analysis. The results take about two weeks.
What does the RAST test for?
The RAST test is a blood test that is used to see if an individual’s blood contains antibodies for a specific substance, such as peanuts or pollen. These antibodies are called immunoglobulin E, or IgE antibodies. If a person’s blood contains lgE antibodies that are specific to a certain substance, it means they are allergic to that substance.
How much does an allergy test RAST cost?
For a patient not covered by health insurance an allergy test typically costs $150 to $300 for a consultation with an allergist, plus $60 to $300 total ($3 to $5 per allergen) for the much more commonly used skin prick test, or $200 to $1,000 total ($10 to $20 per allergen) for a blood test known as a RAST test.