WHAT ARE FOOD ALLERGIES?
What you need to know
A food allergy is a health condition where your body’s immune system overreacts when you eat certain foods. Food allergies are either immunoglobulin E (IgE)–mediated or non–IgE-mediated:
IgE-mediated
- Caused by IgE antibodies, which trigger your body to quickly release chemicals such as histamine
- Usually occurs in minutes to up to 2 hours after eating a food allergen
- Symptoms may present as:
- An itchy sensation inside the mouth, throat, or ears
- A raised itchy red rash (urticaria, or “hives”)
- Swelling of the face, around the eyes, lips, tongue, and roof of the mouth (angioedema)
Other symptoms may also be seen. Always consult your doctor.
Non–IgE-mediated
- Not caused by IgE antibodies
- Usually occurs up to several hours after eating a food allergen
- Gastrointestinal symptoms such as vomiting, diarrhea, and abdominal pain are common
How does IgE cause food allergies?
IgE is the most common cause of food allergy. The abnormal immune response of a food allergy begins when someone eats a food and their immune system makes a type of antibody, called IgE, against an allergen in the food.
When a person with IgE antibodies eats the same food allergen again, the allergen binds to the IgE antibodies, which causes certain immune cells to release chemicals such as histamine from mast cells. These chemicals cause different symptoms of the food allergy reaction. In severe cases, a reaction may occur if the allergen is inhaled or touched even without eating.
It’s more than nuts
More than 160 foods cause IgE-mediated food allergies. Here are the most common food allergens in the United States:
When do food allergies usually develop?
Children and adults can develop food allergies at any time, but they often begin within the first 2 years of life.
How common are food allergies?
The prevalence of food allergy in children (aged 0 to 17 years) has been increasing in the United States.
8% of children
Approximately 5.6 million US children have a diagnosed food allergy. About 40% of US children with a food allergy are allergic to multiple foods.*
11% of adults
Approximately 37 million US adults have a food allergy. About 50% of US adults developed their allergy in adulthood.*
FOR CHILDREN AND ADULTS
In an online survey study,
36% of people with a single food allergy and 53% of people with multiple food allergies had asthma.
People who have both asthma and food allergy may have more severe allergic reactions to food.
*Based on estimates for 2024.
How common are food allergy accidents?
51% of children
with 2 or more food allergies have been treated at an emergency department.
3.4 million patients
have a food allergy–related emergency room visit each year in the US.
Know the symptoms of food allergies
Food allergy symptoms can vary greatly and look different in each person. Symptoms of an IgE-mediated allergic reaction may involve the skin, stomach, heart, and lungs. They can surface in one or more of the following ways (some of these can also be with non–IgE-mediated):
- Vomiting and/or stomach cramps
- Hives
- Shortness of breath
- Wheezing
- Repetitive cough
- Tight, hoarse throat; trouble swallowing
- Swelling of the tongue, affecting the ability to talk or breathe
- Weak pulse
- Pale or blue coloring of skin
- Dizziness or feeling faint
- Shock or circulatory collapse
- Anaphylaxis, a severe, life-threatening allergic reaction
Food allergies or food intolerance?
It’s important to know the difference
Food intolerance is often confused with food allergy. Here are the important differences between the two that you should know about:
Food allergies
Food allergy is a condition in which eating certain foods leads to an abnormal immune response. Food allergies are either immunoglobulin E (lgE)-mediated or non–IgE-mediated reactions.
Unlike food intolerance, food allergies can be associated with anaphylaxis, which is a serious reaction that includes difficulty breathing and can be potentially life-threatening—requiring immediate medical attention.
Food intolerance
Food intolerance doesn’t involve the immune system. For example, an intolerance to lactose—a sugar found in many milk products—can lead to bloating or stomach pain.
Food intolerance is not associated with severe reactions such as anaphylaxis.
“I was taking some sort of rescue medications for accidental exposure to milk 1 out of every 3 times that I ate out.”
—Lauren, XOLAIR patient
Lauren received compensation to share her story. Individual results may vary.
You’ve got a whole support network on your side
From diagnosis to treatment, everyone’s food allergy experience is unique. The Support For You program is designed with YOU in mind. Access free 1-on-1 sessions and learn about programs that may help you save on XOLAIR.
Explore real stories of navigating life with food allergies
Meet patients and caregivers as they share their food allergy experiences and their decisions to include XOLAIR as part of their food allergy action plan.
Patients featured received compensation to share their story. Individual results may vary.