From the Guidelines
To confirm milk and wheat allergies, a combination of diagnostic tests, including skin prick tests, specific IgE antibody tests, elimination diets, and supervised oral food challenges, should be performed under the guidance of an allergist. The most recent and highest quality study, 1, published in 2022, highlights the importance of a multi-faceted approach in diagnosing food allergies.
Diagnostic Tests
- Skin prick tests: involve placing small amounts of milk or wheat proteins on the skin to observe for reactions
- Specific IgE antibody tests: measure immune response to these allergens
- Elimination diets: completely remove milk or wheat from the diet for 2-4 weeks to see if symptoms improve, then reintroduce them carefully while monitoring for reactions
- Supervised oral food challenges: conducted in a medical setting where the patient consumes gradually increasing amounts of the suspected allergen while being monitored for reactions
Importance of Medical Supervision
As noted in 1, oral food challenges are considered the gold standard for confirming a diagnosis of food allergy, but they should only be performed under medical supervision due to the risk of severe allergic reactions.
Limitations of Single Tests
Single tests alone can sometimes yield false results, as highlighted in 1 and 1. Therefore, a combination of tests is necessary to confirm a diagnosis of milk or wheat allergy.
Conclusion is not allowed, so the answer will be ended here.
From the Research
Confirming Milk and Wheat Allergy
To confirm milk and wheat allergy, several diagnostic tests can be used, including:
- Skin prick tests: This test measures the skin's reaction to a small amount of the allergen, in this case, wheat or milk. However, according to the study 2, the skin prick test was only positive in 23% of infants with challenge-proven wheat allergy.
- Patch tests: This test involves applying a small amount of the allergen to the skin and observing the reaction over a period of time. The study 2 found that 86% of infants with challenge-proven wheat allergy had a positive patch test for wheat.
- Specific IgE measurements: This test measures the levels of IgE antibodies in the blood, which are associated with allergic reactions. The study 2 found that only 20% of infants with challenge-proven wheat allergy had elevated IgE concentrations to wheat.
- Oral food challenge: This is considered the gold standard for diagnosing food allergies, including milk and wheat allergy. The study 2 used a double-blind, placebo-controlled or open wheat challenge to confirm the diagnosis of wheat allergy in infants.
Diagnostic Accuracy
The diagnostic accuracy of these tests varies, with:
- Skin prick tests having a specificity of 1.00, but a lower sensitivity 2
- Patch tests having a lower specificity of 0.35, but a higher sensitivity 2
- Specific IgE measurements having a specificity of 0.93, but a lower sensitivity 2 It is essential to note that a positive test result does not always confirm an allergy, and an elimination-challenge test is necessary to confirm the diagnosis, especially in patients with positive patch test results 2.