Does my Child have a Food Allergy or a Food Intolerance?

JanelMS, RD, LDN, CBS

Read time: 6 minutes

What to know about food allergies and food intolerance in children

  • Recognize food allergy symptoms

  • Understand the difference between food allergies and food intolerances

  • Identify symptoms of food intolerances

  • Tips on how to manage your child’s food allergies or food intolerances


We want to do right by our children, and that includes feeding them nourishing foods. But what if your little one is reacting to something they’ve eaten? How do you know if this is a food allergy or an intolerance?

Knowing what to look for and how to handle a food allergy or intolerance is key to easing anxiety around feeding your little one.

Read on to learn about the signs and symptoms of an allergy versus an intolerance and understand how to react if needed.

What is the difference between a food allergy and an intolerance?

While these terms are sometimes used interchangeably, there is a big difference between a food allergy and food intolerance.

An allergic reaction happens when the body's immune system reacts to a protein in a food, triggering a protective response.1 Close to 8% of all children in the United States have a food allergy, a number that has been growing over the last couple decades.2 Symptoms are normally more severe than a food intolerance and can occur throughout the body.

With a food allergy, the person must usually take the allergen out of their diet all together.

On the other hand, a food intolerance happens when the body has difficulty digesting a certain food or reacts to a substance within the food.3, This results in mostly gastro-intestinal symptoms.4, It is estimated that 15 to 20% of the population in the United States suffers from food intolerances.5

Usually someone with a food intolerance can still eat small amounts of the food without it causing symptoms.3,

Wondering if your child has a food allergy or intolerance? Reach out to our team of registered dietitians and lactation consultants for free! They’re here to help on our free to live chat from Monday – Friday 8am-6pm (ET), and Saturday – Sunday 8am-2pm (ET). Chat Now!

Which foods cause allergic reactions?

While over 160 foods have been linked to food allergies, only eight foods account for about 90% of all reactions:6 Milk, eggs, peanuts, tree nuts (walnuts, pecans, almonds, cashews, pistachios), soy, wheat (gluten), fish, shellfish (shrimp, crab and lobster). Food manufacturers must label foods that contain these eight allergens.

Since sesame seed allergy affects over 1 million people, starting in January of 2023 sesame will be added as the ninth top allergen.7,8 At that point, food manufacturers will have to label foods that contain sesame as well.7,

Learn more: Introducing Major Allergens to your Infant

What symptoms do food allergies cause?

Symptoms of an allergic reaction may involve the skin, respiratory system, digestive track, and/or the cardiovascular system.1 It’s important to know that while a mild reaction may happen when eating the food the first time or two, it’s possible that reactions become more severe the more the food is eaten.1

Symptoms of a food allergy may include:

Hives (red spots that look like bug bites), eczema

  • Itchy skin rashes (eczema)

  • Swelling to the lips and face

  • Sneezing, coughing, wheezing

  • Nausea, vomiting, diarrhea, cramping

  • Throat tightness, difficulty breathing

  • Light-headedness

  • Loss of consciousness

  • Anaphylaxis9,17,1

Anaphylaxis is a severe and potentially life-threatening allergic reaction that can occur within seconds to up to 2 hours after exposure to an allergen.10 It can, among other things, cause a sudden drop in blood pressure and impair breathing. If your child has known allergies, make sure you speak to your physician or allergist to get an emergency plan in place so that you are always prepared.

There are rare cases in which food allergy symptoms are delayed up to 6 hours. This may be seen in children who develop eczema as a food allergy symptom or in the case of Food Protein-Induced Enterocolitis Syndrome (FPIES).1

Learn about celiac disease (gluten allergy): Meal Plan for Gluten Free Infants and Toddlers

Which foods cause a food intolerance or sensitivity?

A food intolerance happens when someone lacks the enzymes needed to digest a food, are intolerant to naturally occurring substances in the food, or are sensitive to food additives.3,11

Foods that may cause reactions include: Fructose, lactose and other FODMAPs (easily fermented carbohydrates found in a variety of foods); wheat, histamine (often found in processed meats, cheeses, and some produce), and food additives.11

What symptoms do food intolerances cause?

Most noticeable symptoms of a food intolerance happen in the digestive track.4, However, there are studies indicating that symptoms may go beyond the gut. Because of the variability of symptoms, food intolerances are much more difficult to diagnose.

Symptoms of food intolerances may include:

  • Gas, bloating, abdominal pain4,9,

  • Diarrhea, constipation4,9,

  • Being fussy or crying after eating18

  • Irritable Bowel Syndrome (IBS)12

  • Headaches13

  • ADHD14,16

  • Chronic fatigue15

Sometimes the symptoms of an intolerance and of a true allergy can overlap. For example, lactose intolerance and milk protein allergy have similar symptoms but stem from very different causes.9,

If you suspect your child has a food intolerance, speak with your child’s pediatrician.

Read more: Does My Baby have a Milk Allergy or Lactose Intolerance?

What to do if you suspect your child has a food allergy or intolerance

Chat with baby’s pediatrician if you suspect a food allergy

If you think your little one may be allergic to a food, call their pediatrician immediately and begin avoiding the suspected food. The pediatrician may perform allergy testing to confirm the reaction, or they may have your child see an allergist.

And if your child experiences any severe reactions (like difficulty breathing, swelling, severe vomiting or diarrhea), call 911 immediately.

Avoid foods completely if your little one is allergic to them

Thoroughly read food labels and ingredient lists of products, avoid products inadequately labeled or that you suspect may contain an allergen your child should avoid. Many food manufacturers have phone numbers you can call to ask about allergens in their products.

If you child is severely allergic, you may need to be careful of cross-contact and cross-contamination. This is when your child touches a surface that an allergen was in contact with before.19 For example, if your child has a peanut allergy and they touch a counter where a peanut butter sandwich was made previously but the surface was not cleaned well, your child may have an allergic reaction.

Another cross-contamination example is if a knife or other utensil was used for one allergenic food before being used for another food without being washed between.

Read more: Guidance when Raising a Child with Food Allergies

Be prepared to combat exposure to an allergen

If you or your child has already been diagnosed with a food allergy, keep antihistamine and epinephrine (if prescribed by your physician) with you and/or your child always. Speak with your child’s pediatrician or allergist to have a plan of action in place should exposure to an allergen occur.

Keep a food and symptom log if you suspect a food intolerance or sensitivity

If you feel your infant or child may be showing signs and symptoms of an intolerance, start keeping a food log. Include all foods, beverages, time and date of consumption, and timing and type of symptoms.

You may also want to keep track of outside factors, such as school or daycare, change of laundry detergent, soap, lotion, or other household products, as well as smoke exposure etc. These may sometimes play a role in environmental sensitivities or allergies.

A log will help you identify which foods or environmental culprits your little one is reacting to.

Read more: Is Your Baby Reacting to Something in Your Breastmilk?

Meet with a dietitian

Your child’s pediatrician may recommend seeing a dietitian. A dietitian can work with you to manage your little one’s diet and help make sure they continue getting all the nutrients they need even while taking out some foods.

Should it be difficult to identify the food(s) your child has an intolerance to, the dietitian may recommend, and help administer, an elimination diet.20,24 This is a temporary change in the diet when one or more foods are taken out for a few weeks to see if symptoms improve (elimination phase), and then are added back in to see if symptoms return (reintroduction or challenge phase).21

The reintroduction phase helps make sure you aren’t restricting more foods than necessary in your little one’s diet.

For a food intolerance, find the threshold amount

Often a food intolerance or sensitivity may allow for a small amount of the food to be eaten without it triggering symptoms.23 This is called the “threshold” amount.25 For example, with lactose intolerance many people are able to tolerate 4 to 8 ounces of dairy per day (such as yogurt or cow’s milk) without suffering any symptoms.23

This means that you may not have to completely eliminate a food from your child’s diet if they are sensitive or intolerant to it. Use some trial and error, and keep a food log, to figure out how much your little one can have without it triggering symptoms.

Working with a dietitian can help with this process.

The good news

While some allergies are never outgrown, when it comes to egg, milk, wheat, and soy allergies, it is estimated that 80 to 90% of children outgrow their allergy by the age of 5 years.9,22 Track your child’s allergy with their pediatrician to see if the allergy begins to fade away.

Let's Chat!

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Our Happy Baby Experts are a team of lactation consultants and registered dietitian nutritionists certified in infant and maternal nutrition – and they’re all moms, too! They’re here to offer personalized support on our free, one-on-one, live chat platform Monday - Friday 8am-6pm (ET), and Saturday - Sunday 8am-2pm (ET). No appointment needed, no email or sign-up required. Chat Now!

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For more on this topic, check out the following articles:

Guidance when Raising a Child with Food Allergies

Introducing Major Allergens to your Infant

Major allergens: While pregnant and breastfeeding