The Food and Drug Administration (FDA) recently released a notice for allergen extracts used for food allergy testing. The warning is about severe allergic reactions, called anaphylaxis [anna-fih-LACK-sis], following negative skin prick tests for food allergies.

This is not new information about skin prick tests used to diagnose a food allergy.

Allergists often use skin prick tests to help diagnose food allergies, as well as allergies to other substances such as pollen, animals, and mold.

This new warning only confirms what allergy experts know. It is NOT a new warning for people concerned about being diagnosed with and managing food allergies.

What Does the Notice From the FDA Say?

On March 3, 2023, the FDA released a statement saying they are requiring changes to the prescribing information for food allergy extracts used in skin prick tests. The new safety warning notes that anaphylaxis has been reported following some negative skin tests. It continues to add that health care providers should consider a blood test or oral food challenge to confirm a negative skin test in some cases.

Why Did the FDA Issue This Warning?

This new recommendation from the FDA is based on peanut extracts from one company during a very specific time period. There is no evidence that this applies to peanut extracts from other companies or other time periods, or toward any other food allergen skin testing.

The FDA chose to apply a warning to all food allergy extracts used in skin testing based on these few instances.

What Do People Need to Know About Anaphylaxis and Skin Testing for Food Allergies?

Allergen extracts go through very strict quality control. Although this warning may seem unsettling, it shows that the system is working to ensure high-quality products. The maker (ALK-Abelló) of the peanut allergen extract mentioned above voluntarily recalled certain lots.

Here are some things to keep in mind in light of this news from the FDA:

• If your child is eating a food without any issues, you do not need to remove the food from their diet.
• If your child tested negative to a food on a skin prick test in the past, you do not need to worry about the accuracy of those results.
• A history of allergic reactions to a food outweighs allergy test results. For example, if your child has an allergic reaction every time they eat peanuts but they have a negative skin test for peanuts, they may have an allergy to peanuts. Your doctor may do additional testing to confirm diagnosis.
  
  

If your child has a history of symptoms when eating a certain food and has a negative result on a skin prick test, guidelines recommend that their allergist do more testing. Allergists can order serum IgE testing (a type of blood test) for that allergen or do a medically-supervised oral food challenge (which is the gold standard for diagnosing a food allergy) to help confirm the allergy.

False positives on food allergy tests are traditionally the bigger issue. They can lead to improper diagnosis of a food allergy. This can cause people to unnecessarily restrict their diet, lead to higher food and medical costs, and reduce quality of life. A positive test result for a food by itself does not necessarily confirm a food allergy. A doctor looks at a number of things before diagnosing a food allergy. Food allergy testing should not occur if there is no history of symptoms after eating a specific food.

The FDA has not yet addressed “at-home” allergy tests. These tests look for the wrong antibody. Many people are using them to self-diagnose food allergies based on incorrect information and interpretation of test results without considering medical history.

For these reasons, we recommend that you see a board-certified allergist if you think you or your child has a food allergy. An allergist should ask about full medical history and review the results of diagnostic tests when diagnosing food allergy.

Where Can I Learn More About Food Allergy Testing?

Read these resources to learn more about food allergy testing:

• More information about food allergy testing (This article explains why people may receive false positives or false negatives.)
• More information about oral food challenges
• Peanut Allergy Diagnosis: 2020 Practice Parameter Update from the Joint Task Force on Practice Parameters
  
  

Medical Review: Written with guidance from Matthew Greenhawt, MD; Michael Pistiner, MD, MMSc; and David Stukus, MD