Here’s the Difference Between a Food Allergy and a Food Intolerance

Did you know 50-90 percent of self-reported food allergies are wrong?1  When you suspect a food allergy it is tempting to self-diagnose, but you could be creating dietary restrictions that can lead to poor nutrition. For accurate diagnosis of food allergy, a board-certified allergist should be consulted. In the meantime, let’s find out the difference between a food allergy and food intolerance.

To make it simple, a true food allergy causes an immune system reaction that may affect numerous organ systems in the body. The range of symptoms can be from mild to severe to life-threatening.

Symptoms for a food allergy can be any of the following2:

  • Tingling or itching in the mouth or throat.
  • Hives, urticaria or itching.
  • Swelling of the lips, face, tongue and/or throat.
  • Wheezing, nasal congestion or trouble breathing.
  • Abdominal pain, diarrhea, nausea or vomiting.
  • Dizziness, lightheadedness or fainting, caused by a drop in blood pressure.

While any of these symptoms can happen, the most severe include difficulty breathing and a drop in blood pressure that can be life-threatening. This is commonly referred to as anaphylaxis. The only approved treatment for anaphylaxis is epinephrine. Anaphylaxis is rare, but those with food allergies and their caregivers should be trained to treat it if it should occur.

A food intolerance usually causes digestive issues and will not cause a severe or life-threatening reaction. If you have a food intolerance, you may even be able to eat small amounts of this food with no ill effects. With both a food intolerance and food allergy, you can prevent a reaction by not eating the food at all.

When you suspect a food allergy, it can be tempting to try an over the counter panel test. These tests, however, are not considered evidence-based.  They don’t require medical doctor’s order and they also don’t provide expert assistance in interpreting the results. An allergist can order blood or skin tests to help support a history of a reaction to a specific food. Testing should be limited to the specific food that has caused a reaction, not broad testing of many different foods at one time. Research shows that reliance on large panel tests, those that test for reactions to many foods at one time, can result in over diagnosis. This is a particular problem with food allergy where unnecessary avoidance of foods can lead to restricted diets and in some cases, to malnutrition.4 Blood and skin tests alone are not adequate to diagnose food allergies. Blood tests are not proven to diagnose or detect food intolerances (or food sensitivity, which is a term poorly defined in the literature).

Diagnosing a food allergy is complex and should be conducted by a board-certified allergist. Blood and skin-prick tests are valuable tools for identifying an allergy but have high rates of false-positives and are not conclusive in diagnosing food allergies on their own. Oral food challenges are the gold standard for food allergy diagnosis.3

When you believe you or someone you care for has a food allergy, it’s important to be evaluated and properly diagnosed by a board-certified allergist. Food allergies are much too serious to assess without an expert.


The National Peanut Board has contributed more than $35 million over the past two decades to peanut allergy solutions.



  1. NIAID Sponsored Expert Panel. (2010). Guidelines for the Diagnosis and Management of Food Allergy in the U.S.: Report of the NIAID-Sponsored Expert Panel. J of Allergy Clin Immunol, S1-S58.
  2. Food allergy. (2019, November 02). Retrieved February 08, 2021, from
  3. Guidelines for the Diagnosis and Management of Food Allergies in the U.S. Available at
  4. Portnoy J. M. (2011). Appropriate allergy testing and interpretation. Missouri medicine108(5), 339–343.