Food Allergies and Your Baby: Ways To Keep Infants Safe and Healthy

Developing severe allergic reactions is one of the biggest fears new parents face when beginning their babies’ food journey. Understanding food allergies and timing for exposing your baby to possible allergens is important to keeping them safe and healthy.

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If you’re about to begin the exciting time of complementary feeding—or introducing your baby to solid foods in addition to milk feedings—you’ve probably thought about the possibility that they might develop food allergies.

If this is more than a thought but instead a downright fear, I promise that you are not alone.

We might think that by waiting to feed infants the foods that might cause reactions we’re giving them a better chance to develop a strong immune system and fight against those reactions. In fact, many believe this to be true. But this couldn’t be further from the truth.

What Are Food Allergies?

Food allergies are immune system reactions that happen after eating certain types of food. While any food can cause allergic reactions, there are 9 foods that cause them most frequently:

  • Milk (80% outgrow this allergy by age 5)
  • Eggs (80% outgrow this allergy by age 16)
  • Peanuts (only 20 to 25% outgrow)
  • Tree nuts (only 20% outgrow)
  • Wheat (45% outgrow)
  • Soy (80% outgrow by age 16)
  • Fish (most commonly developed in adulthood)
  • Shellfish (most commonly developed in adulthood)
  • Sesame (only 20 to 30% outgrow)

Reactions to these foods can occur minutes to several hours after exposure and include the following symptoms:

  • Hives
  • Flushed skin
  • Stuffy/runny nose
  • Rash
  • Face, tongue, or lip swelling
  • Vomiting/diarrhea
  • Coughing or wheezing
  • Change in breathing or difficulty breathing
  • Losing consciousness or going limp

These symptoms might all seem scary, but knowing what they look like can help you keep your baby safer if they develop food allergies. And as a parent, you may ask if food allergies are the same as food intolerances. The answer is no. Unlike true food allergies, food intolerances do not involve the immune system, although they might have the same symptoms.

Why Is Allergen Introduction So Important For Infants and Why Don’t We Wait?

Before the LEAP (Learning Early About Peanut Allergy) study from 2015, doctors commonly recommended that parents wait until their infant is 3 years or older before introducing foods that cause the most severe allergic reactions, such as peanuts. This study found that exposing infants to peanuts early led to a decrease in severe reactions by up to 80%, leading to changing guidance from doctors—from “wait” to “expose early, expose often”.

So, why does this work?

Your baby’s immune system at 4 to 6 months—when we typically begin complementary feeding—is generally immature and not quite as rigid as it will be when your baby is older. Because it’s immature, the immune system doesn’t create as many antibodies, which attack proteins in foods, leaving your baby a better chance of developing a tolerance as their body learns to recognize them.

When we wait to expose our babies to different types of food, we give their immune system the opportunity to get better at its job. This may mean getting a little too aggressive about trying to keep your baby safe from potential harm, sometimes leading to violent reactions to an otherwise harmless peanut.

Another benefit of exposing your baby to allergens early on while their immune system is still learning is that the vast majority of initial allergic reactions to foods are mild. Secondary reactions tend to be much more serious. Once a severe reaction occurs, it is much harder to get rid of the underlying allergy. So once your doctor gives the okay to start offering allergens, go for it!

How Do We Introduce Babies To Food Allergens?

Now that you know how important it is to “expose early, expose often” you might be wondering how to offer these foods to your baby.

Time of Day

When offering your baby a new food that has the potential to cause reactions, the best time of day is in the morning with their first solid food meal, and on a day when no other potential allergens are being offered. This gives you the rest of the day to watch for any reactions and allows you to keep track of which food caused it. 


Start with small amounts and build up as your baby handles them well.


It is outdated guidance that all foods be served individually for three days in a row, but you’ll want to follow this advice for allergens. If you offer peanut butter once, for example, continue offering it for another two days before introducing another allergen.

Unfortunately, tolerance isn’t a “one and done” event. In order for your baby to develop a strong tolerance to these foods, they need to be offered with regularity if there have been no reactions. 

When To Call Your Doctor

Even before starting to introduce solid foods to your baby, you should have a conversation with your doctor to assess any risk factors that might make your child more likely to develop food allergies. These risks include having:

  • eczema
  • asthma
  • a parent or sibling with food allergies
  • any reaction to any food previously

Chances are that your doctor will still advise that you give your baby allergenic foods. But if there is enough risk they might recommend that you keep certain medications on hand or do your first exposure in the doctor’s office. Doctors will not give your baby a blanket allergy test without these risk factors or an initial reaction.

Even though initial reactions to allergenic foods are most often the mildest, if your baby experiences any reaction you’ll still want to let your doctor know. Initial mild reactions can lead to severe reactions on second exposure, so make your doctor aware no matter how mild a reaction may be. If your baby experiences any reaction that affects their breathing, call 911.

Reactions that can affect their breathing include the following:

  • Swelling of the tongue
  • Persistent coughing
  • Wheezing
  • Seizure
  • Losing consciousness or going limp

How Do We Treat Food Allergies?

Unfortunately, there is no medicinal treatment for food allergies that have already developed. Medicines can be used to treat the symptoms of reactions, but usually preventative steps—such as avoiding the problematic food—are needed to help keep children safe.


As your baby grows, introducing new foods into their diet is an exciting time. But because guidance on introducing possible food allergens to your baby has changed over time, it is important to understand what’s best to keep your baby healthy and safe. Here are some key takeaways below:

  • Food allergies can be a danger to babies, yet exposing them to allergens early can help them develop tolerances that can keep them safer.
  • Tolerance is built over time: keep going!
  • Even if infants develop a food allergy, first reactions are often the mildest.
  • If a severe allergic reaction happens, it’s often more difficult to outgrow the allergy.
  • Food allergies can’t be treated with medicines.
  • Expose early, expose often! Yet always talk to your pediatrician before starting the introduction of allergens.

Meet The Expert

Angelina Pizzi

Angelina has been working with children and families for the past 15 years. She has been a certified math and science teacher, a high-profile nanny, and now a parent coach and child nutritionist. She created Adventurous Eating to help as many families as possible develop healthy relationships over mealtimes and raise children who absolutely LOVE to eat well.