Navigating Allergen Introduction: A Comprehensive Guide for Parents

Erin Moore, Nurse Practitioner and Certified Lactation Counselor, answers your top questions about navigating early allergen introduction and how to identify an allergic reaction. 

Starting solids is a fun milestone in a baby’s first year. Unfortunately, sometimes worry can come about when starting new foods. One common concern many families have is, “what if my baby has a reaction to a food?”

This blog post will dive into answering the most common questions parents have while introducing allergens so you can feel confident while feeding your baby.

What is a Food Allergy and Why Do They Matter When Introducing Solids?

A food allergy is when exposure to a food triggers a harmful immune response called an allergic reaction. The allergic reaction occurs because the immune system attacks proteins in the food that are normally harmless. These foods are called allergens.

Over 33 million Americans have food allergies, including 1 in every 13 children. This means that there are roughly two kids in each classroom with a food allergy.

Food allergies are more common than we think and they are on the rise.

The Center for Disease Control and Prevention reports that the prevalence of food allergy in children increased by 50 percent between 1997 and 2011. The prevalence of peanut or tree nut allergy appears to have more than tripled in U.S. children since 1997.

The rise in food allergies makes introduction very important!

What are the Most Common Allergens?

Allergens are substances that trigger allergic reactions in susceptible individuals. While any food can potentially cause an allergic reaction, some are more common culprits than others. 

These are the nine most common allergens that we need to focus on when introducing allergens to our babies:

  • Milk: Cow's milk is a common allergen, affecting both infants and young children. 
  • Eggs: Particularly the proteins found in egg whites, eggs are another prevalent allergen among children.
  • Peanuts: Peanut allergies are often lifelong and can cause severe reactions even in trace amounts.
  • Tree Nuts: Including almonds, walnuts, cashews, and others, tree nut allergies can also be severe and lifelong.
  • Soy: Soybeans and soy products are common ingredients in many foods and can trigger allergic reactions.
  • Wheat: Wheat allergies are different from gluten intolerance or celiac disease and can cause various symptoms.
  • Fish: Allergies to fish, including shellfish, are common and can develop at any age.
  • Shellfish: This includes crustaceans like shrimp, crab, and lobster, as well as mollusks like clams and mussels.
  • Sesame: Sesame is found in common food such as hummus, tahini, and baked goods.

When to Introduce Allergens to Babies

Did you know that until the year 2000, parents were advised to delay introducing potentially allergenic foods until babies turned one? It was thought that this would reduce the risk of developing food allergies.

More recent research suggests that early introduction may be more beneficial. The American Academy of Pediatrics recommends introducing allergenic foods to low-risk babies between 4 to 6 months of age after a baby has started solid foods. Make sure the foods are in a safe form based on your baby’s development - you don’t want to offer your baby foods that are choking risks!

How to Introduce Allergens to Your Baby

When introducing allergenic foods to your baby, it's essential to do so in a safe and controlled manner. Here's a step-by-step guide:

Start with Single Ingredients

Introduce one allergenic food at a time, waiting 2-3 days before introducing another. This allows you to monitor for any adverse reactions and identify the specific allergen if a reaction occurs.

Choose the Right Time

Introduce allergenic foods when your baby is healthy and not experiencing any other illnesses. You want to be able to tell what is happening if your baby has a reaction.

Prepare Appropriately

Cook or prepare the food in a way that makes it easy for your baby to eat. Purees or soft foods are ideal for babies. You can mix allergens with “safe” food that your baby has tolerated multiple times before.

Offer Small Amounts

Begin with a small amount of the allergenic food to gauge your baby's reaction. A teaspoon or less is usually sufficient. Monitor your baby for 10 minutes and then offer more. 

Monitor Closely

Stay vigilant for any signs of an allergic reaction, such as hives, swelling, vomiting, diarrhea, or difficulty breathing. If you notice any concerning symptoms, seek medical attention immediately. 


Allergic Reactions in Infants

Allergic reactions can range from mild to severe and may look different in each person. Common symptoms of an allergic reaction to food include:

  • Hives or rash
  • Swelling of the face, lips, tongue, or throat
  • Vomiting or diarrhea
  • Wheezing or difficulty breathing
  • Loss of consciousness

In severe cases, an allergic reaction can lead to anaphylaxis, a rare but life-threatening condition that requires immediate medical attention. Anaphylaxis can cause a sudden drop in blood pressure, difficulty breathing, and loss of consciousness.

If you have any concerns about a food allergy, please contact your pediatrician or call 911.

Tips for Introduction

Introducing allergenic foods to your baby can be nerve-wracking, but with the right approach, it can be a smooth process. Here are some tips to keep in mind:

  • Consult with your baby’s pediatrician: Before introducing allergenic foods, consult with your pediatrician, especially if you have a family history of food allergies or your baby has other health concerns. They will help you figure out the safest method of introduction for your baby.
  • Ready. Set. Food! is an easy and effective way to introduce allergens and keep them in your baby’s diet. It provides a step-by-step approach to introducing the most common allergens so you can take one thing off your plate. Just open one of the small packets, mix it into a food your baby has already tolerated, and observe for any reactions. The best thing is that Ready. Set. Food! grows with your baby! Keep allergens in your baby’s rotation by using their mix-ins, baby oatmeal, puffs, or bars.
  • Consider offering allergenic foods early in the day: It is recommended that a parent closely monitors their child after allergen introduction. Introducing allergens earlier in the day can ensure that parents have ample time to monitor before bedtime.
  • Be patient if your baby doesn’t eat the allergens right away: It may take several tries before your baby accepts a new food, so be patient and persistent. 
  • Offer foods early and often: Continue to expose your baby to allergenic food daily or multiple times per week. If your baby has a mild reaction to a particular food, consult with your pediatrician before deciding whether to continue offering it.
  • Take photos of any reaction: first, make sure your baby is not in distress. Call 911 if they are. Take photos if they are not - especially if they have rashes. Rashes may change quickly and it can be helpful to see what it looked like at different stages.

Introducing allergenic foods is important for your baby’s health and well-being. Though reactions may be scary, knowing how to handle a reaction may help you feel more confident while starting solids.

All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.