Introducing Major Food Allergens to your Infant

JanelMS, RD, LDN, CBS

Read time: 5 minutes

What to know about introducing food allergens to your baby

  • Learn the major food allergens

  • Understand the latest research about introducing allergens early

  • Recognize the symptoms of a food allergy

Keeping up with the latest food allergy recommendations can seem daunting, especially since new research seems to come out all the time. What causes food allergies and why they’re on the rise remains unclear, but the fact that they are rising cannot be disputed.

Knowing how to introduce food allergens to your baby at the right time and what signs to look for if your little one is allergic can help you feel confident in feeding your little one.

What causes a food allergy?

Roughly 8% of American children have at least one food allergy.1,2 An allergic reaction to food happens when the body's immune system overreacts to a protein in food. Instead of seeing it as harmless, the food is labeled as dangerous, and the body initiates a protective response.3,

Top eight food allergens

Any food has the potential to cause an allergic response, and so far over 160 foods have been identified as potential allergens.4 However, only eight foods account for about 90% of all reactions.4

Top 8 food allergens:

  • Milk

  • Eggs

  • Peanuts

  • Tree Nuts (walnuts, pecans, almonds, cashews, pistachios)

  • Soy

  • Wheat

  • Fish

  • Crustacean Shellfish (shrimp, crab and lobster)

Starting in January 2023, sesame seeds will be added to the list as the ninth major food allergen.

Sesame allergy affects over 1 million Americans, prompting the passage of the FASTER (Food Allergy Safety, Treatment, Education, and Research) Act by Congress in April 2021. This will make sesame the ninth major food allergen.5,6 At that time, all foods with sesame seeds will need to be labeled, just like the current eight major allergens.4

When to introduce food allergens to your infant

The latest research has shown that there is no benefit in delaying the introduction of allergy-causing foods.7 Because of this, the American Academy of Pediatrics (AAP) recommends introducing foods such as eggs, dairy, soy, peanuts, or fish when you introduce solids, no later than 6 months.8

However, if you suspect your baby has an allergic reaction to a food or if you have a history of severe eczema or food allergies, talk to your doctor on how best to introduce allergy-causing foods.

Read more:

Starting Solids: Signs of Readiness

Introducing Solids: First Foods and Textures

What are the symptoms of a food allergy?

Once you introduce a new potential food allergen to your baby, how do you know if your little one has an allergy? Symptoms of an allergic reaction may involve the skin, the digestive system, the cardiovascular system and/or the respiratory tract.9, These symptoms can vary from person to person, and from incident to incident.

It’s important to know that while a mild reaction can occur on one occasion, a severe reaction to the same food may occur when the food is introduced later.3,

Symptoms of a food allergy may include:

  • Hives (red spots that look like bug bites)

  • Itchy skin rashes (eczema)

  • Swelling to the lips and face

  • Sneezing, wheezing, or throat tightness

  • Nausea, vomiting, or diarrhea

  • Pale skin

  • Light-headedness

  • Loss of consciousness

  • Anaphylaxis9,10

Anaphylaxis requires immediate medical treatment. Anaphylaxis is a severe and potentially life-threatening allergic reaction that can occur within seconds or up to 2 hours after a child is exposed to an allergen.3,10 It can, among other things, cause a sudden drop in blood pressure and difficulty breathing.3, If you notice any of these severe symptoms, call 911 immediately.

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.

Read more: Signs and symptoms of food sensitivities and allergies in children

Tip on how to introduce food allergens to your infant

Know if your infant is high risk before introducing food allergens

Discuss your plan to introduce solid foods and allergens with baby’s physician or allergist. Your little one may be at higher risk for food allergies if someone in baby’s family has a food allergy or has a family history of other allergic diseases, such as eczema, asthma, hay fever, or atopic dermatitis.12 Your infant may also be at higher risk if they have known allergies or severe eczema.11,13

Introduce major allergens alongside safe, already well-tolerated first foods

Unless otherwise instructed by your physician, give your baby one major allergen at a time at a rate no faster than one new food every 3 to 5 days.12 Make sure no other new foods are introduced at the same time so you can accurately track any symptoms that may be related to the allergen introduced.

Note that when introducing food allergens, be sure they are in the appropriate texture for your little one’s development. Avoid choking hazards, such as whole peanuts.

You can trial dairy product such as cheese and yogurt before age one, but whole cow’s milk should be avoided until after one year of age. While the reason behind this is unrelated to allergies, it is worth noting because your baby cannot digest whole cow’s milk easily.14

Learn about:

Preventing Choking in Infants and Toddlers

Does my Baby or Toddler have a Milk Allergy or Lactose Intolerance?

Keep potential food allergens in your infant’s diet consistently

Once you’ve introduced a potential food allergen and your little one does well, make sure to offer that food regularly. This will help your infant maintain their tolerance to it.13

Ideas for introducing food allergens in first-food textures

Introduce these allergens in a texture your little one can handle. The below give ideas for purees as well as soft finger foods, depending on the stage your little one is at.

  • Dairy (Cow’s milk): Whole milk yogurt or shredded cheese

  • Soy: Mashed tofu or small cubes of tofu

  • Eggs: Scrambled eggs or small pieces of hard-boiled eggs

  • Peanuts, tree nuts, sesame (best given in butter or powder format): Mix a small amount of nut butter or nut powder into a fruit or vegetable puree or put a very thin layer of a nut butter on strips of toast. The butter or powder may also be added to a smoothie.

  • Fish: Soft, moist, well-cooked fish; mashed or cut into pieces

  • Wheat: Wheat infant cereal such as cream of wheat, wheat-containing teething biscuits, or strips of whole wheat toast with a smidge of butter

Will changing my diet during pregnancy or breastfeeding help prevent allergies in my baby?

Current research indicates that avoiding foods during pregnancy or breastfeeding is not effective in helping to reduce the risk of our babies developing allergies.15 And in fact, there is some evidence that early introduction of allergens during pregnancy and breastfeeding, such as mom including fish and peanuts in her diet, may help to lower the risk of your little one developing allergies to these foods.16

Of course, it is important to avoid any foods that you are allergic to! Additionally, if your breastfed baby has an allergy those foods should be avoided as well.

With this in mind, be sure to eat a wide variety of foods while you are pregnant and breastfeeding. Not only may it help reduce the risk of allergies, but you need the full range of nutrients to grow a healthy baby.

Read more:

Which Nutrients Do I Need During Pregnancy?

What to Eat while Breastfeeding

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

Guidance When Raising a Child with Food Allergies

Major allergens: What to Know When Pregnant and Breastfeeding