Food allergies are an immune response that typically develops in early childhood. Around 32 million people have food allergies in the United States. The most common food allergies are eggs, fish, milk, peanuts, shellfish, soy, tree nuts and wheat.
While it’s not known exactly what causes food allergies, many people outgrow their allergies to milk, eggs, soybeans and wheat. However, food allergies to peanuts, tree nuts, fish and shellfish typically don’t go away.
Food Allergy Symptoms
Food allergies can present differently in different people. Symptoms can range from something mild, like a swelling of your lips, to more severe, like loss of consciousness.
Some food allergy symptoms include:
- Abdominal cramps
- Coughing or wheezing
- Difficulty breathing
- Dizziness and/or lightheadedness
- Face, tongue or lip swelling
- Flushed skin or rash
- Hives
- Itchy skin
- Loss of consciousness
- Sneezing
- Stuffy, itchy nose
- Swelling of the throat and vocal cords
- Tingling or itchy feeling in the mouth
- Vomiting and/or diarrhea
Symptoms of Food Allergy in Babies
Babies are not generally allergic to breastmilk, but they can be allergic to foods their mothers eat that can come through the breastmilk. If your baby is allergic to something in your breastmilk, they will typically show signs and symptoms within 24 hours.
Some signs of food allergy in a baby include:
- Diarrhea
- Fussiness during and/or after feedings
- Green or bloody stools
- Inconsolable crying for long periods
- Rash, eczema, dermatitis, hives or dry skin
- Sudden waking with discomfort
- Vomiting
- Wheezing or coughing
The most severe allergic reaction is anaphylaxis, a life-threatening reaction that can close your airway. If you or someone you know is experiencing anaphylaxis, get to an emergency room immediately.
Food Allergy Diagnosis
If you think you or your child may have a food allergy, your primary care provider can perform food allergy testing to find out. Your provider may also refer you to see an allergist for testing.
Food allergy testing can include:
- Blood tests. These tests measure the levels of the allergy antibody IgE in foods.
- Elimination diets. During an elimination diet, you will stop eating certain foods and see if your symptoms disappear. Your primary care provider may suggest slowly reintroducing that food to see if your symptoms return.
- Oral food challenge. This test involves eating the food you may be allergic to in the presence of your allergist. They will feed you larger and larger doses of the suspected food until you experience symptoms or a food allergy is ruled out. Because this test could trigger an anaphylaxis response, you should only try it under medical supervision.
- Skin prick tests. During this test, the allergist will place drops of fluid that contain food allergens onto the patient’s arm or back. They will then scrape or prick the skin to let some of the solutions get underneath the surface of your skin. The test should not be painful or cause bleeding. Monitoring the reaction to allergens during this timed test confirms potential food allergies.
How to Treat Food Allergies
There is currently no cure for food allergies, so the best way to avoid flare-ups is to avoid the foods that trigger a response. FDA-approved oral immunotherapy is currently available for peanuts. Treating your food allergies depends mainly on your symptoms. You will want to always carry an EpiPen and an antihistamine with you.
Antihistamines block histamines, which are released when an allergen is inside your body. Most of the time, histamines work in your body’s favor, but they also cause your food allergy symptoms, like a rash or hives. For more severe reactions, particularly in anaphylaxis, you may need epinephrine, the only medication to help during anaphylaxis. Also known as an EpiPen, it is a prescription injection and works by relaxing the airway muscles and tightening the blood vessels. Talk with your primary care provider to provide an EpiPen prescription and an anaphylaxis plan for severe food allergies.
When It’s Not Food Allergies
There are a few illnesses that produce similar symptoms to food allergies. Those illnesses include:
- Asthma. Rarely, food allergens may lead to symptoms like those seen in asthma, such as coughing, wheezing, etc. According to the Centers for Disease Control and Prevention, children with food allergies are more likely to develop asthma, but just because your child may have one disease doesn’t necessarily mean they will have the other. Asthma causes lung inflammation and is typically aggravated by environmental allergens or exercise.
- Celiac disease. This disease is caused by a reaction to the gluten protein common in wheat, rye and barley. People with celiac disease may experience gastrointestinal issues if they eat gluten.
- Eczema. Also known as atopic dermatitis, eczema can cause dry, itchy and red skin. Food allergies may be associated with eczema, especially if the eczema is severe and presents early in infancy.
- Eosinophilic esophagitis. This disease develops when certain white blood cells (eosinophils) collect in the esophagus. Because of this, the esophagus can get inflamed, which makes it difficult to swallow food. Food allergens can be a trigger for eosinophilic esophagitis.
- Lactose intolerance. People with lactose intolerance are unable to digest the sugar lactose found in dairy products.
- Oral allergy syndrome. Oral allergy syndrome is caused by eating raw fruits and vegetables with proteins like pollen proteins. People with oral allergy syndrome experience symptoms like an itchy mouth when they eat certain foods. The symptoms usually go away after a few minutes.
More to Read
Should I Take My Child to the Emergency Room?
Healthy Sleep Habits Mean a Happy Child
How to Get a Baby to Sleep: Developing Healthy Habits from the Start
Pregnant? Here’s Why You Should Consider Breastfeeding.
Medically reviewed by Anupama Kewalramani, MD.
