With up to 10% of the general population being affected by food allergies, it is likely that you or someone you know has this potentially life-threatening condition. What’s worse is that there is currently no cure for food allergies, and affected individuals can only rely on food avoidance and treating their reactions as they occur. This has made it increasingly important for everyone to get tested for food allergies.

What Are Food Allergies?

Food allergies are defined as a negative health effect caused by an immune response to a certain food. These negative health effects can range from mild rashes, hives, and facial swelling, to anaphylaxis, which is a severe and potentially fatal reaction that can affect the person’s ability to breathe. The foods that can cause these reactions in an affected individual are called allergens, and while each person’s triggers will be different, the eight most common allergens (milk, eggs, fish, shellfish, peanuts, tree nuts, wheat and soybeans) account for 90% of food allergies.

However, food allergies should not be confused with food intolerances or seasonal allergies, despite being named similarly. Food intolerances, such as lactose intolerance, result from non-immune responses and their symptoms are typically limited to digestive problems. Similarly, seasonal allergies are typically caused by airborne allergens instead of allergens present in food, causing them to be separate from food allergies as well.

What Is Food Allergy Testing?

If you suspect that you or a loved one may have a food allergy, food allergy testing performed under the supervision of a licensed allergist can help determine if this is truly the case. There are three main types of food allergy testing: oral food challenges, skin prick tests, and serum tests. 

The first of these, the oral food challenge, is the gold standard of allergy testing, but also carries the largest risk of triggering a severe allergic reaction. In an oral food challenge, the allergist will give a small amount of the suspected allergen to the person to eat. The allergist will then observe them to determine whether they actually have an allergy to the given food and/or determine the amount of allergen they can safely consume. If a severe reaction occurs, the allergist will be ready to intervene with the necessary treatment, but nevertheless, oral food challenges are still not recommended for people who have a history of anaphylaxis. This test is also usually performed only after other tests that provide preliminary information on the severity of the allergic reaction that the person may have.

The second type of allergy test, the skin prick test, revolves around exposing the skin to the allergens instead of ingesting them. The allergist will usually place a small drop of allergen extract on the person’s forearm, and then prick it into the person’s skin. This process is mostly painless, and can be repeated for numerous allergens, as long as they are adequately spaced apart. The allergist will usually also prick histamine, an inflammatory chemical, and saline into the skin as positive and negative controls, respectively. Once the allergen is inside the skin, it triggers the release of histamine, which leads to a visible “wheal and flare” response on the surface of the skin, with swelling surrounded by a ring of redness. The allergist will take a measurement of the size of the swelling approximately 15-20 minutes after pricking the skin, with a larger size indicating a higher likelihood of having a food allergy towards that allergen.

The third type of allergy tests are serum tests, which test for the presence of immune proteins in the person’s blood. In this test, the person only needs to submit a blood sample to the laboratory for testing and is not exposed to any potential allergens, making it the least likely test to trigger a reaction. If the person has allergies, their blood will contain above average amounts of specific immune antibody proteins that are each associated with a certain allergen that the person is sensitive to. In the lab, the amount of each of these immune proteins is analyzed, and a higher concentration of immune proteins against an allergen indicates that the person has a more severe food allergy. However, it is important to note that serum tests tend to be more quantitative but less sensitive than skin prick tests in general.

Conclusion

Given that the prevalence of food allergies is increasing worldwide, we as a society need to increase awareness about this condition. The first step in being able to better handle any disease is diagnosis, and this is why allergy testing is crucial. Regardless of whether or not you believe you have a food allergy, consider being allergy tested. You just might save your own life, or the life of a loved one, by being informed and prepared.