Food Allergy Myths and Facts

Fact: Food allergies can be a life-threatening disease. 

They are more than just an itch or a stomachache. Food allergies can cause symptoms such as hives, coughing, swelling of the face and tongue, difficulty breathing, and loss of consciousness. Food allergies are not only life-threatening, they are also life-altering. People with food allergies must always be vigilant to avoid foods they are allergic to.

Fact: Even a trace amount of a food allergen can cause a severe reaction called anaphylaxis in some people. 

The food a person is allergic to must be completely removed from their diet for them to stay safe and live well. Avoiding cross-contact between a safe food and a food allergen is just as important as avoiding the allergen itself. Cross-contact happens when a food that someone is allergic to accidentally touches another safe food someone is going to eat. That safe food is dangerous for the person with a food allergy.

Fact: Food allergy reactions are unpredictable. 

The way a person’s body reacts to a food one time can’t predict how they will react the next time. There is no way to know if a reaction is going to be mild, moderate, or severe. People with a food allergy should always be prepared with emergency medication, just in case.

Fact: Food intolerance does not involve an immune system reaction. 

While food intolerances can cause great discomfort, they are not life-threatening. A food allergy, on the other hand, can be fatal.

Fact: Positive skin prick or blood test results for a food allergy are not always accurate and can often give “false positive” results. 

This means that the test is “positive” even though you are not allergic to the food being tested. An Oral Food Challenge (OFC) is the gold standard of tests and should be discussed with a board-certified allergist. An OFC happens in the doctor’s office and involves eating the suspected food allergen to see if a reaction happens.

Learn more about diagnostic tests for food allergies.

Fact: No single food allergy poses a greater threat than another.

While 9 foods account for most food allergies in the U.S., virtually any food can cause an allergic reaction. Even a very small amount of the problem food is enough to cause a reaction.

Fact: A food allergy can occur at any age, well into adulthood.

You can even develop an allergy to a food you have safely eaten many times before. In fact, about half of people who have a food allergy to shellfish experience their first allergic reaction as an adult.

_{Warren CM, Aktas ON, Gupta RS, Davis CM. Prevalence and characteristics of adult shellfish allergy in the United States. J Allergy Clin Immunol. 2019 Nov;144(5):1435-1438.e5. doi: 10.1016/j.jaci.2019.07.031. Epub 2019 Aug 8. PMID: 31401288; PMCID: PMC6842441.}

Fact: Antihistamines (like Benadryl® or Zyrtec®) can help relieve some symptoms like an itchy mouth or skin, but they DO NOT stop anaphylaxis. 

Epinephrine is the only approved medication to stop anaphylaxis and should be given first and fast.

Fact: It is possible to outgrow your food allergies with age.

For example, many children outgrow food allergies to milk, soy, eggs, and wheat. However, allergies to peanuts, tree nuts, fish, and shellfish are less likely to be outgrown.

Fact: Symptoms can start within a few seconds of eating a food allergen, but it can take up to 2 hours for symptoms to appear.

Sometimes, after the first symptoms go away, a second round of symptoms can occur without re-exposure to the allergen. This can happen between 1 and 48 hours after the first symptoms (or sometimes longer), even after treatment has been given. This second set of symptoms is called a biphasic reaction.

_{Ichikawa M, Kuriyama A, Urushidani S, Ikegami T. Incidence and timing of biphasic anaphylactic reactions: a retrospective cohort study. Acute Med Surg. 2021 Jul 30;8(1): e689. doi: 10.1002/ams2.689. PMID: 34354840; PMCID: PMC8323456}

Fact: Allergens can appear in unexpected places. For example, fish or shellfish are sometimes dipped in milk to reduce their fishy odor, posing a problem for people with milk allergy.

Never assume anything about how a food has been made or served. Always read food labels and ask questions about ingredients before eating a food that you have not prepared yourself.