Powered by
Al Borg Diagnostics
Food Allergy Test: Important Information About It
Food allergy affects 8% of children and up to 4% of adults, causing a range of symptoms from mild to life-threatening allergic reactions. Understanding essential information about a food allergy test is crucial, which helps identify and avoid allergenic foods. (1)
What is a Food Allergy Test?
Food allergy occurs when the immune system overreacts to harmless food proteins (an allergen). It can occur in response to any food or multiple types. (2)
Regarding a food allergy test, no perfect test confirms or rules out an allergy to a specific food. Instead, various diagnostic methods are available to identify the foods a person is allergic to and should avoid. We will explain them in detail in the following paragraphs. (1)
What are the Types of Food Allergy Tests?
Here are the main types of food allergy tests:
1. Skin Prick Tests:
Skin prick tests provide insights into the types of foods that trigger an allergic reaction and should be avoided. The results can be observed within 20-30 minutes.
- How is this test performed?
A liquid containing a tiny amount of the food allergen is placed on the skin of the patient’s arm or back, followed by a gentle prick with a small sterilized needle to allow the liquid to seep under the skin. A control solution without allergens is also applied to another area for result comparison. (3)
- How are the results interpreted?
The appearance of wheals (resembling the bump from a mosquito bite) indicates an allergic reaction, while the absence of any wheals or responses suggests no allergy. (3)
2. Blood tests
In this test, the immune system’s response is measured by determining the amount of specific allergy-related antibodies known as Immunoglobulin E (IgE) to specific foods that are being tested, such as milk, eggs, peanuts, wheat, soybeans, shellfish, codfish, and others. (3)(6)
It is important to note that Immunoglobulin E (IgE) is a type of antibody produced by B cells in response to allergens, pathogens, cancer cells, and other threats to the body. (4)
Generally, this test is less accurate than the skin prick test, and the results are typically available about a week after the test. (3)(1)
- How is this test performed?
This test collects a blood sample from a vein in the patient’s arm using a small needle. The blood and various types of food are then placed in a vial for analysis in the laboratory. (5)
- How are the results interpreted?
The results are interpreted based on the level of Immunoglobulin E (IgE) and comparing it to the reference range, which depends on the person’s age, as follows: (6)
- Newborns: 0 – 4 International Units per milliliter (IU/mL).
- Older children and adults: 0 – 148 International Units per milliliter (IU/mL).
The table below shows how the results are typically rated and interpreted: (6)
| Rating of specific IgE level | Interpretation |
|---|---|
| Less than 0.35 | Unlikely |
| 0.35 - 0.69 | Doubtful significance |
| 0.7 - 3.49 | Possible |
| 3.5 - 17.49 | More Possible |
| 17.5 - 49.99 | More likely |
| 50 - 100 | Very likely |
| Above 100 | Extremely likely |
3. Other Tests
In addition to the previous laboratory tests, here are other tests that a doctor may request to identify food allergies:
- Elimination Diet
In this test, suspected food allergens are eliminated from the diet for some time, which can be a week or more (meaning the person is prohibited from consuming them for a certain period). Then, one type of food is added to the diet at a time, and the appearance of allergy symptoms is monitored.
It is important to note that elimination diets aren’t foolproof. (1)
- Oral Food Challenge
In this test, the patient is given a small amount of the suspected food allergen, and the quantity is gradually increased while monitoring the appearance of symptoms. It is necessary to inform you that this test is performed in a doctor’s office. (1)
Are Food Allergies Serious?
Food allergies are a medical condition that can be life-threatening, so it is essential to always take them seriously.
While food allergy reactions can sometimes be mild, causing only minor abdominal pain or hives, in other cases, they can escalate into severe allergic reactions that are life-threatening and known as anaphylactic shock. (2)(1)
Therefore, do not hesitate to visit any branch of Al-Borg Diagnostics to perform a food allergy analysis, which is one of the tests in the Allergy Package.
References:
- https://www.mayoclinic.org/diseases-conditions/food-allergy/symptoms-causes/syc-20355095
- https://www.foodallergy.org/resources/what-food-allergy
- https://acaai.org/allergies/allergic-conditions/food/
- https://labs.selfdecode.com/blog/immunoglobulin-e-ige-antibody-test/
- https://www.chop.edu/treatments/allergen-specific-ige-testing
- https://dermnetnz.org/topics/immunoglobulin-e-tests
