About Food Allergies

About Food Allergies

About PreventAllergies.org

In recent decades, there has been a significant rise in the number of food allergies with more than 1 in 10 suffering from a food allergy today. Fortunately, there is new research that shows that introducing allergenic foods early and often can help significantly reduce the risk of developing food allergies in infants by up to 80%. Our goal is to provide families with the information, tools and support to bring this new research home to reverse the troubling rise in food allergies. We are a group of physicians and parents who are committed to make food allergy prevention accessible for every parent.


What is A Food Allergy?

A food allergy occurs when the body’s immune system mistakenly responds to certain foods that it thinks are harmful. Our immune systems defends and protects us from foreign invaders like certain viruses and bacteria.

Food allergies occur when the immune system over-defends and treats certain proteins in foods as foreign invaders. These proteins are called allergens and our immune systems makes special allergy antibodies called IgE antibodies to these allergens to help fight them off. These antibodies trigger a reaction each time a person eats a food they are allergic to.


Symptoms Of A Food Allergic Reaction

A food allergic reaction can lead to symptoms like hives, swelling of lips/tongue, stomach upset, breathing problems, and other symptoms.

In babies, hives and vomiting are the most common symptoms of a food allergic reaction. These symptoms usually occur within seconds to minutes and almost always within 2 hours.
In addition, one reaction can vary widely from the next in the same person.

Food allergies are most common in children, but a food allergy can occur at any age


Food Allergy Reaction Symptoms

Symptoms for affected body parts

What is anaphylaxis?
When the symptoms are severe and involving more than one organ system, it’s classified as anaphylaxis, and this can be life-threatening.


IgE-mediated v. Non-IgE mediated food allergy

IgE-mediated food allergy is different than non-IgE mediated (delayed-type) food allergy.

  • For instance, some infants have a delayed allergy to milk, which can cause blood and mucus in the stool hours to days after the ingestion of milk.
  • Another example is Food protein-induced enterocolitis syndrome (FPIES) which is 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.

Food Allergy Testing

Validated food allergy tests like skin prick tests or blood tests look for the presence of IgE antibody. If the tests are positive, they show that a person produces IgE antibodies to food allergens. But blood and skin tests alone cannot be used to diagnose food allergy. A person does not have a food allergy unless they also have clinical symptoms. There is also a chance that a person could have a “false positive” on their skin or blood test.

Validated food allergy tests like skin prick tests or blood tests look for the presence of IgE antibody. If the tests are positive, they show that a person produces IgE antibodies to food allergens. But blood and skin tests alone cannot be used to diagnose food allergy. A person does not have a food allergy unless they also have clinical symptoms. There is also a chance that a person could have a “false positive” on their skin or blood test.

The only way to definitively diagnose a food allergy is with an oral food challenge. This test 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.

The only way to definitively diagnose a food allergy is with an oral food challenge.

This test 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.

Learn More

Top Resources for You

What does an allergic reaction look like?

What are the top allergens affecting children?

What’s my baby’s risk of developing a food allergy?

How can I prevent food allergies before they start?