All About Food Allergies in Babies and Children

Food allergies affect around 8% of children in America. Learn about the causes, symptoms, and whether you can prevent food allergies when starting solids.

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It's estimated that food allergies affect up to 8% of children in America, according to the Centers for Disease Control and Prevention (CDC). That’s about one out of every 13 kids. For these children, eating certain foods triggers an immune system overreaction that can cause anything from itching and eczema to difficulty breathing and life-threatening anaphylactic shock.

The problem is also growing; the incidence of food allergies increased 50% between 1997 and 2011. Scientists aren't exactly sure why, but theories include greater awareness among parents and doctors, lower immunity because kids come across less bacteria, and lack of exposure to common allergens early in life.

So what are signs of food allergies? Can you prevent them from developing in the first place? Here, experts share all you need to know about food allergies in babies, toddlers, and children.

What Causes Food Allergies?

Doctors don't fully understand why some children develop food allergies and others don't. However, "eczema is one of the earliest markers of an allergic person," says Amal H. Assa'ad, M.D., a professor of pediatrics and director of Cincinnati Children's Hospital Medical Center's Food Allergy Clinic. In fact, up to 40% of babies with moderate to severe eczema also have food allergies, according to research by Parents advisor Hugh Sampson, M.D., director of the Jaffe Food Allergy Institute at Mount Sinai Hospital, in New York City.

A family history of eczema, asthma, and allergies also raises the stakes. "You may inherit the susceptibility to become allergic. It's not anything that the mother does when she's pregnant or breastfeeding or anything that the father does," says Dr. Assa'ad. Some children just get a bigger share of the genes that predispose them to food allergies.

Also note that food allergies are different from food intolerances, though they might have similar symptoms. That's because food intolerances don’t affect the immune system. "People with food intolerances are not able to digest certain foods because their bodies lack the specific enzyme needed to break down that food," says Ruchi Gupta, M.D., associate professor of pediatrics at Northwestern University Feinberg School of Medicine in Chicago. "For example, if you're lactose intolerant, you're missing the enzyme lactase, which breaks down lactose, a sugar found in milk and other dairy products. Food intolerances can cause great discomfort, but they are not life-threatening the way a food allergy can be."

Most Common Food Allergies 

Because babies don't typically eat a wide range of foods, the most common allergies are to cow's milk, notes Scott H. Sicherer, M.D., of the Jaffe Food Allergy Institute at Mount Sinai School of Medicine, in New York City. Up to 7% of infants have trouble digesting milk. Many parents confuse this with lactose intolerance, an inability to digest the milk protein lactose that is common in older kids and adults. But this condition is rare in infants; it sometimes shows up temporarily after a stomach virus but quickly goes away.

Your baby, toddler, or child can be allergic to a wide range of foods. But in the United States, there are nine common culprits.

Common Food Allergens

These nine foods account for more than 90% of food allergies in America, according to the U.S. Food and Drug Administration (FDA).


  • Cow’s milk
  • Eggs
  • Fish
  • Peanuts
  • Sesame
  • Crustacean shellfish
  • Soy
  • Tree nuts
  • Wheat


The nine foods on this list are legally subject to regulatory requirements from the U.S. Food and Drug Administration (FDA). Manufacturers must accurately label these allergens on products, and food facilities must take steps to avoid cross-contamination. 

In some cases, children might also experience oral allergy syndrome (OAS), where the body confuses proteins found in certain pollen with those in food items. Because the immune system believes the proteins are closely related, it triggers allergy symptoms in people exposed to them, according to the the American Academy of Allergy, Asthma & Immunology (AAAAI). This is called cross-reactivity. For example, the AAAAI says if you’re allergic to ragweed, you may also react to bananas or melons, which have similar proteins. 

Signs of Food Allergies in Babies and Children

With a food allergy, the immune system reacts to a harmless food as if it were a threat and creates histamines and antibodies to fight it. "All that means is that the digestive system isn't able to comfortably handle it," says pediatrician Gwenn Schurgin O'Keeffe, M.D.

Symptoms typically appear within seconds to a few hours after the person has eaten, touched, and/or inhaled an allergenic food. The signs of food allergies in babies and children might include:

  • Tingling in the mouth
  • Swelling of the tongue, throat, lips, face, or other body parts
  • Difficulty breathing
  • Hives
  • Red, itchy skin 
  • Congestion
  • Wheezing
  • Vomiting
  • Abdominal cramps
  • Diarrhea
  • Dizziness or lightheadedness
  • Red blood in the diaper (This can be a sign of allergic colitis, a type of milk allergy that irritates the colon)
  • Anaphylaxis

Anaphylaxis is the most serious allergic response, which is a potentially fatal reaction that produces a form of shock. "If your child has trouble breathing, a swollen tongue, and becomes flushed and wheezy, don't drive to the hospital—call an ambulance immediately," warns Dr. O'Keeffe. Other signs of  anaphylaxis include throat tightness, chest tightness, and "tingling in the hands, feet, lips or scalp,” says the AAAAI.

Every exposure to the trigger may increase the reaction's severity. And it doesn't matter if your 2-month-old has never tasted peanuts, for example: If you had a peanut butter sandwich for lunch, they can be exposed to it through your breast milk or your skin, explains Dan Atkins, M.D., a pediatric allergist at Denver Children's Hospital and National Jewish Health.

As their immune systems mature, most children outgrow allergies to egg and milk by the time they enter elementary school. Food allergies can be triggered at any age, even after a food has been ingested for years, but allergies to peanuts and different types of fish are typically the most life-threatening and often manifest themselves early and last for life.

How to Diagnose Food Allergies

While young food-allergy sufferers number in the millions, Dr. Sicherer stresses the importance of securing a trustworthy diagnosis before drawing any dietary conclusions. Restricting a child’s diet without your pediatrician's guidance carries risks of its own. "The biggest danger is that you create a child who has a narrow range of food choices," says Frank Greer, M.D., past chair of the American Academy of Pediatrics (AAP) committee on nutrition and professor of pediatrics at the University of Wisconsin Medical School, in Madison.

If your child has stomach problems or is fussy after meals, talk to your pediatrician and visit an allergist. Sometimes the problem isn’t related to food allergies at all: "I consider many issues," says Dr. O'Keeffe. For example, “when babies don't take well to formula, incorrectly mixing the powder (not striking the right balance of water to formula) is a common cause.” Infants might also react to overfeeding or a gas-inducing food in their nursing parent’s diet. 

If they suspect allergies, your pediatrician may have you eliminate items one by one from your child’s diet—or from your own, if you're breastfeeding—to figure out the problem. Some doctors also recommend a skin prick test, in which an allergist pricks food-protein extracts into your child’s skin to see which ones cause a red, itchy bump. (But note that skin testing isn’t usually conducted on infants younger than 6 months). The allergist may also request a blood test, sent to a medical laboratory, to determine food allergies. 

If your child is diagnosed with an allergy, you'll have to steer clear of their trigger foods. If it’s milk-related, doctors will usually put formula-fed babies on a hypoallergenic formula. Just remember, while food allergies can be frustrating and even scary, they don't necessarily last forever, says Dr. Sampson. For example, the the AAP says 80-90% of “egg, milk, wheat, and soy allergies” no longer exist by age 5.

Can You Prevent Food Allergies While Pregnant or Breastfeeding?

In the past, conventional wisdom held that avoiding highly allergenic foods during pregnancy and breastfeeding— as well as withholding them from a child during their early years—could reduce the risk for food allergies. But recent evidence has turned that advice upside down. Now it seems there may be no reason to say “no” to allergenic foods.

If you’re pregnant, it's OK to eat highly allergenic foods unless you are allergic to them. There’s no proof that staying away from them lowers allergy risks in babies. In fact, cutting them from your diet may cause more harm than good, as most allergenic foods provide crucial nutrients for you and your baby. For example, omega-3 fatty acids in fish and shellfish promote fetal brain development, and the folate in peanuts helps prevent neural-tube defects, such as spina bifida.

What’s more, avoiding allergenic foods while breastfeeding has not been shown to provide any benefit to your baby. However, researchers do believe that breastfeeding itself may help ward off food allergies. "Exclusive breastfeeding—no formula—for four months or longer is the best thing," says Dr. Greer. If your breastfed baby reacts to something you eat, avoid it.

As for the opposite tactic—going out of your way to eat allergenic foods during pregnancy or breastfeeding— there's no evidence that doing so offers any protection against allergies either, says Dr. Greer.

Smart Feeding Strategies for Starting Solids

According to the American Academy of Pediatrics, offering your baby allergenic foods is permitted starting at four to six months; just be sure to watch for any allergic reaction (symptoms include hives, itchy eyes or mouth, vomiting, pale skin, fainting, difficulty breathing, and swelling of the eyes, tongue, or lips).

Indeed, “several studies show that the early introduction of highly allergenic food can lead to a lower rate of food allergies,” says Katie Marks-Cogan, M.D, co-founder and Chief Allergist of Ready, Set, Food. “This age lets you mold the immune system away from allergies.” 

Between four to six months, depending on your baby's readiness, you should introduce them to new single-ingredient infant foods, three to five days apart—think fruits, vegetables, and cereal grains, suggests the AAAAI. After babies successfully tolerate some of these less allergenic foods, parents can gradually introduce allergenic items like egg, dairy, fish, and nuts. Record everything that your baby eats for several weeks as well as any related symptoms (eczema, fussiness, gas). Visit your doctor if you notice a concerning pattern.

If your infant is diagnosed with asthma, eczema, or a food allergy, follow your doctor's instructions on the timing of solid foods, says Dr. Greer.

Are you nervous about feeding your baby allergenic foods? Dr. Marks-Cogan stresses that you shouldn't worry. "We know that feeding infants allergenic foods is inherently safe," she says. "Allergic reactions are milder in children than in adults. That's why we believe that less than 1 year of age is the safest time to be introducing allergenic foods."

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Parents uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Maternal peanut consumption and risk of peanut allergy in childhood. CMAJ. 2018.

  3. Breastfeeding and Allergic Diseases: What's New? Children (Basel). 2021.

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