Our Food Allergy Glossary for Parents and Families

We’ve compiled this list of the most essential terms related to food allergies and related conditions, to help parents and families stay informed. We’ve also included links to other food allergy resources.


A food protein that someone’s immune system treats as a foreign invader, and that causes an allergic reaction when the person eats that food.


When the body’s immune system mistakenly responds to certain foods that it thinks are harmful.


A severe, life-threatening allergic reaction. When the symptoms of a food allergy are severe, and involve more than one organ system, it is classified as anaphylaxis. Anaphylaxis can lead to constricted airways in the lungs, severe lowering of blood pressure and shock, and suffocation by swelling of the throat.

Biphasic Reaction

A second anaphylactic reaction that occurs 4 to 24 hours after the initial anaphylactic reaction, after the first reaction is treated with epinephrine. It can be less severe, just as severe, or more severe than the first reaction. Due to the possibility of a biphasic reaction, people with severe food allergies must have access to two epinephrine auto-injectors at all times

Celiac Disease

A serious, gluten-related autoimmune disease that affects the intestines. If someone with celiac disease consumes gluten, it damages their small intestine.

Early and Sustained Allergen Introduction

The process of gradually introducing common allergenic foods to your baby early and often, starting between 4-11 months of age and continuing 2-7 times a week for several months. Recent groundbreaking clinical studies have offered scientific evidence that early and sustained introduction of allergenic foods, such as peanut, egg, and cow’s milk is effective.


Eczema is a general term for a group of inflammatory skin conditions. Atopic dermatitis, the most common type of eczema, causes red, dry, and itchy skin. In infants, this form of eczema usually affects the face, scalp, and skin creases, but can also affect other areas of the body. Research shows that infants with eczema are at the highest risk for developing food allergies.


A life-saving, injected medication for treating allergic reactions; the only medication that can stop anaphylaxis. Also known as adrenaline. Promptly administering epinephrine using an autoinjector (such as an EpiPen) during early symptoms of anaphylaxis may help prevent serious consequences.

Food Allergy

Food allergies cause the immune system to over-defend the body. When someone has a food allergy, their immune system mistakenly treats proteins in certain foods as foreign invaders. As a result, their body develops an allergic reaction each time they consume a food that they are allergic to. Symptoms of a food allergic reaction include hives, swelling of lips/tongue, stomach upset, breathing problems and other symptoms.

Food Intolerance

Adverse health effects caused by foods, which do not involve the immune system. Unlike food allergies, food intolerances are rarely ever life-threatening, and there is no validated test to diagnose a food intolerance. Common food intolerances include lactose intolerance and gluten-related disorders.


Food Protein-Induced Enterocolitis Syndrome; a non-IgE mediated disorder that usually occurs in young infants. Symptoms include chronic vomiting, diarrhea, and failure to gain weight or height. When the allergenic food is removed from the infant’s diet, symptoms disappear. Milk and soy protein are the most common causes.

Gluten-Related Disorder

Any disorder that causes intolerance to gluten, a protein present in many grains such as wheat, rye, and barley. These disorders range from mild gluten intolerance to the more serious celiac disease. Symptoms include skin swelling, shortness of breath, and gastrointestinal problems.

Gluten-related disorders are intolerances, not allergies; there is no such thing as an allergy to gluten. An allergy to wheat is different than a gluten-related disorder because it causes an allergic immune response to a protein specifically found in wheat. Meanwhile, gluten-related disorders are in response to gluten, which can be found in grains other than wheat. It is unknown what mechanisms cause this response to gluten.

IgE Antibodies

Proteins produced by the immune system to defend the body, which reside in the bloodstream. When IgE is working properly, it defends against parasites and other possibly harmful substances that enter the body. It causes the body to develop coughing, wheezing, and hives when these substances enter the bloodstream.

However, when someone has an IgE-mediated allergy to a certain food, their immune system makes special IgE antibodies to these allergens to help fight them off. These antibodies can help the cells cause a reaction each time a person eats a food they are allergic to.

IgE-Mediated Food Allergy

A food allergy that causes someone’s immune system to develop IgE antibodies to certain allergenic foods, such as milk, egg, peanut, or tree nuts, to help fight them off. Allergic reactions from IgE-mediated food allergies occur within minutes to hours of the person consuming the food.

Non-IgE Mediated Food Allergy

A food allergy that involves different parts of the immune system, other than IgE antibodies. Allergic reactions with this type of allergy are more delayed, and occur within hours to days of food consumption. They often cause symptoms in the GI tract, such as vomiting, diarrhea, and blood and mucus in the stool. Non-IgE mediated food allergies are also known as delayed-type food allergies.

Oral Food Challenge

A test that exposes a person to their potential allergenic food in small doses, slowly increasing over time with careful observation in a medical facility, to watch for signs of an allergic reaction. It is the only way to definitively diagnose a food allergy, but it can be risky.

Stepwise Introduction

A method of allergen introduction that starts with a low dose of an allergen and gradually increases to a higher dose, for maximum safety.

Vitamin D

A vitamin that the body produces when it is exposed to sunlight. It is essential to helping the body maintain strong bones and teeth. Multiple studies suggest that vitamin D deficiency in a baby may result in an increased risk of food allergies.

504 Plan

A plan that details how a person with a disability will receive full participation in the benefits of public school. Having a food allergy falls into the disability category because major life activities can be impaired, such as breathing and eating, that would ultimately prevent a child from accessing the curriculum. A 504 Plan is essentially the written blueprint for how a school needs to accommodate your child in school.

Introduce Allergens Safely and Easily with Ready. Set. Food!

All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.