Introducing Food Allergens to Baby

Published: December 2023

Last Updated: February 19, 2026

Introducing egg, peanut, and other common allergens early and serving them often can help prevent food allergies from developing. Our pediatric pros explain why—and how to safely introduce common allergens as soon as your baby is ready to start solids.

Looking for a step-by-step guide to introducing allergens? The Solid Starts App can help. Start your free trial.

Key Points

✔ Introduce early and serve often

The evidence is clear: food allergies can be prevented by introducing common allergens like peanut and egg in infancy and regularly serving them, especially for babies with an increased risk of food allergy.

✔ Introduction can usually begin at home

Most babies can begin allergen introduction as soon as they are ready to start solids around 6 months of age. However, you may decide to start earlier (around 4 months of age) if your baby has eczema or an existing food allergy. 

✔ Consistent exposure over time is key

Once a food allergen has been introduced, you need to regularly offer it (ideally twice a week) to lower the chances of your baby developing an allergy to that food. 

Why Doctors Recommend Starting Early

In the United States, food allergies in children rose an astounding 50% from 1997 to 2011 and the prevalence of peanut and tree nut allergies tripled during this time. Interestingly, this is roughly the same period of time in which parents were advised to refrain from introducing peanuts and other allergens until well beyond the first birthday.

That began to change after 2015, when a groundbreaking study demonstrated how the early introduction of peanuts to at-risk babies could reduce the risk of developing peanut allergy by as much as 81%. In other words, delaying peanut introduction could actually increase the likelihood of peanut allergies developing. This landmark study led medical professionals to revise their recommendations around the introduction of peanut and extrapolate the study’s findings to other food allergens like egg, cow’s milk, and wheat. Allergists and other medical professionals now recommend introducing many common food allergens well before a baby’s first birthday.

This shift in guidance may have helped turn the tide. In recent years, food allergies to peanut have dramatically decreased among children in the United States. In 2025, a major study confirmed the link between recommendations for early allergen introduction and a significant decrease in food allergies in babies and toddlers at risk of developing food allergies. Our hope is that food allergies will continue to decline as more families take advantage of the preventative benefits of introducing allergens early and regularly serving them.

Top Allergens for Babies

Although it is possible to be allergic to any food, the most common food allergens in the United States are those listed below. Learn more about common food allergens around the world. 

Is my baby at risk for food allergies?

There are two major risk factors that signal a baby may be at greater risk of developing a food allergy: eczema (especially when severe) and existing food allergy.

How to Introduce Food Allergens to Babies

Introducing food allergens doesn’t have to be scary. You can start with a very small amount of the allergen to minimize any possible reaction and slowly work up to larger servings. For step-by-step guidance, download the Solid Starts App. 

1. Assess the risk

If the risk is low, proceed with allergen introduction at home. 

2. Be prepared

Review the symptoms of an allergic reaction before you begin. While an allergic reaction is unlikely, it’s best to know what one looks like just in case.

3. Choose a day to start

Pick a day when you are able to closely observe your baby. The introduction can take place over the course of one day (at breakfast, lunch, and dinner, for example) or on consecutive days.

4. Choose a food 

Choose one common food allergen to get started. We recommend starting with peanut or egg because the evidence for the protective benefits of early allergen introduction is strongest with these common food allergens.

5. Go one at a time

Complete one allergen introduction before beginning the introduction of another. This way, if there is a reaction, you’ll know which food was responsible. 

6. Prepare the food

Start with a small quantity (the smaller the quantity of allergen ingested, the less severe an allergic reaction may be) and gradually work up to offering more. Subscribe to the Solid Starts App to get step-by-step guidance for introducing each common food allergen, including quantities, schedules, and more. 

7. Start early in the day

Start at breakfast or right after a morning nap. This way, it may be easier to contact your doctor for guidance in the unlikely event of a reaction. Most reactions occur shortly after exposure, which is why it is best to introduce allergens when at least one adult can focus their full attention on baby, ideally for at least two hours and without distraction from other children or activities.

8. Start with a small taste

Scoop a small amount with the tip of a spoon or your finger, then hold it near their face, and wait for a moment to let them observe the food. They may lean in with their mouth and try to taste—let them. If they do not budge, slowly move it a little closer to their face, then pause and give them another opportunity. 

If they hesitate, but otherwise seem engaged, you can gently touch the spoon, teether, or finger to their mouth or tongue, but don’t force it. You want baby to associate food with positive experiences, and forcing food into baby’s mouth does not help achieve this goal. If they are not actively engaged, turn their head, or push the spoon, teether, or finger away, they are communicating to you that they want to stop. Take a break or end the meal. You can always start again later. 

Once they’ve tried their first taste, offer more tastes until you’ve offered all of the food you’ve prepared, or they are showing signs that they’re done… whichever comes first. It’s okay if they do not consume all of the food you’ve prepared. Just a small taste is enough to get the introduction process started. 

9. Watch for signs of an allergic reaction

After baby has a small taste, move on to your next activity while observing baby. Ideally keep baby in just a diaper or periodically check the skin on their stomach, chest, and back for any signs of rash or redness. If baby shows no signs of a reaction after 15 minutes, proceed with your day (but stay alert). Most reactions occur within minutes (but up to 2 hours) after exposure. 

If there are no symptoms of an allergic reaction after a couple of hours, offer the allergen again, and repeat the steps above. A baby may not have an allergic reaction the first time they are exposed to the food, so be watchful as you gradually increase the quantity served. The allergen introduction is complete after the third serving. 

10. Aim for regular exposure 

Once an allergen is introduced, serve it at least once a week, and ideally 2 to 3 times a week until at least 6 years of age. It’s okay if you need to take a break when your baby is sick or you are traveling. The goal is to offer food allergens frequently when possible to help your child reap the full preventative benefits of early allergen introduction. 

Food Allergies Around the World

The United Nations and World Health Organization have established the Codex Alimentarius (Codex), a set of international food standards, guidelines, and codes of practice designed to ensure the safety of the global food supply.

The Codex guidelines recommend disclosure of the following food allergens:

These foods comprise the majority of food-induced allergic reactions in most areas of the world. However, common food allergens vary worldwide and are influenced by genetics, the foods most consumed in those regions, and cross-reactivity with airborne allergens, among other factors.

Africa

Asia

Central America, South America & Caribbean States

Europe

North America

Southwest Asia 

Southwest Pacific 

Frequently Asked Questions

Should I delay allergen introduction? 

Not unless advised by your doctor. You should introduce common food allergens, especially egg and peanut, as soon as your baby is ready to start solids, or earlier if your baby has an increased risk of food allergy. Delaying introduction can actually increase the risk of food allergies developing. 

What allergens should I introduce to my baby first? 

Start with peanut, egg, or cow’s milk. You do not need to follow a prescribed order of allergens, but you should prioritize these allergens because they are the most common food allergens in babies and they are staple foods across different cultures. Aim to introduce at least one of these foods every few days, ideally starting by the second or third week of starting solids. Once you’ve introduced peanut, egg, and cow’s milk, proceed with introducing other common food allergens that align with your family’s dietary preferences.

Can I introduce food allergens to my baby with my breast milk? 

Although some food protein does pass to baby through breast milk, this is not a reliable way to introduce or maintain exposure to common food allergens, and so doesn't "count" as early introduction.

Can I introduce a new allergen with an allergen that is already well-tolerated? 

Yes, as long as the well-tolerated allergen has been regularly served (ideally twice a week) since it was introduced. If the well-tolerated allergen has not been served in the last week or so, we recommend introducing the new allergen on its own or alongside another food that baby has been regularly eating. 

Can I introduce tree nuts with mixed nut butter? 

No. It is possible to be allergic to one tree nut but not others. Introducing tree nuts separately lets you rule out food allergy to one variety before introducing a different one. Once all tree nuts in mixed nut butter have been introduced separately, it is a great way to keep up exposure to allergens. 

How much counts as exposure? 

If your baby doesn’t consume the entire serving of allergen offered when you offer it, that’s okay. Relatively modest quantities of allergen exposure (~2 grams of allergen protein per week) can be effective for allergy prevention, as long as it is regularly offered over time. Subscribe to the Solid Starts App for guidance on how to help baby who won’t touch food. 

Should I wait a few days between each new food?

No. You don’t need to wait 3 to 5 days between introducing new foods. That said, you should introduce only one common allergen at a time. It is perfectly fine to introduce an allergen with other new foods baby has not tried, though for ease, many parents prefer serving a new allergen on its own or only alongside foods baby has already safely eaten.

Waiting a few days before introducing each new food can significantly limit the timely introduction of different tastes and textures, and potentially increase the risk of food allergy in the future. In general, the benefits of introducing a variety of new foods outweigh the risks of a potential reaction or sensitivity.

Do I need to buy specialty puffs or powders for allergen introduction and maintenance?

No. It is not necessary (and it is generally not cost-effective) to rely on powders or medicalized processed food products when introducing food allergens or keeping them in the diet. A food allergen may be introduced by safely preparing it in a way that meets baby’s age and developmental ability, and you can look up any food in our First Foods® database to see how it’s done. However, powders and puffs can help with allergen introduction or maintenance when there is limited access to food (while traveling, for example), or if baby has a medical condition that interferes with the introduction of solid food. 

What are the first signs of food allergy in babies?

Review the full list of allergy symptoms in babies before you get started. Most babies will never experience an allergic reaction, but it can happen—and it is important to understand how to spot an allergic reaction and how to take action if it happens. 

Is a rash from acidic foods an allergic reaction? 

Not usually. Acidic foods like berries, citrus, pineapple, and tomato often cause a harmless rash on the skin that comes into contact with the juices, typically around the mouth and chin. Contact rashes usually dissipate with a gentle cleanse after mealtime. Pat with a wet washcloth; don’t rub to avoid further irritating the skin. To help protect the skin from contact rashes, you can apply a barrier ointment (pure petroleum jelly or a plant-based oil and wax combination) to the face before mealtime.

If the rash is widespread (such as all over the torso, arms, and legs), it is more likely to be an allergic reaction than a contact rash and you should seek immediate medical guidance. Check out Allergy Symptoms in Babies to learn more.

I think my baby had an allergic reaction. What should I do?

Talk to your doctor. They can help sort out whether symptoms are more consistent with a true food allergy, a food intolerance, or a temporary reaction related to illness, eczema, or feeding stage. This step matters. Unnecessary elimination of food from your child’s diet can sometimes increase the risk of an allergy developing, rather than reduce it. 

After you connect with your doctor, they will likely attempt to confirm or rule out a food allergy. No single test tells the whole story—the history matters most. They will need to know what foods they’ve eaten, including what foods you believe caused the reaction, as well as when allergy symptoms appeared. 

If a food allergy is confirmed, your doctor can advise you on how to safely feed your child while avoiding food allergens. They can also prescribe emergency medication and review an action plan for how to treat reactions and eventually reintroduce the food when it is safe to do so. Food allergies often fade over time, and in some cases, early and careful management—under medical guidance—can improve the chances of developing long-lasting tolerance.

How should I reintroduce an allergen if baby has a reaction? 

Consult your doctor before attempting to reintroduce any food that has triggered an allergic reaction in your child. If baby has experienced an allergic reaction to a food, do not offer the food again until you can make a plan with licensed professionals, ideally a pediatric allergist. Allergic reactions can be unpredictable, and a child who experienced only a mild reaction at first might experience a more severe reaction later on. Your medical team can guide you on how best to proceed, and they may recommend reintroduction under medical supervision. This way, baby can be monitored and immediately treated if an allergic reaction occurs. 

What is an IgE-mediated allergy?

IgE-mediated allergies are what most people think of when they think of a food allergy. They result in symptoms very quickly after allergen ingestion, often within minutes. IgE-mediated allergies are diagnosed by confirming a clinical history of reactivity with a positive blood test or skin prick test at the allergist’s office. Several IgE-mediated food allergies (such as cow’s milk, egg, soy, and wheat) are commonly outgrown in early childhood.

What is a non-IgE-mediated allergy?

Non-IgE-mediated food allergies are immune hypersensitivities that do not involve the production of IgE antibodies. Instead, other parts of the immune system, such as white blood cells, are activated. Symptoms typically take longer to appear than IgE-mediated allergies (from a few hours to days after eating) and they show up in various ways, including skin rashes and gastrointestinal symptoms. 

There is no standardized testing available for non-IgE-mediated food allergies, so the diagnosis is based on clinical history. The recommended treatment? Avoid the allergen and reassess at regular intervals to determine if the allergy has been outgrown. Epinephrine and antihistamines will not treat symptoms of non-IgE-mediated food allergy. However, in certain cases, anti-nausea medication, steroids, and biologics may be used to counteract the bothersome symptoms and inflammatory response. Check out FPIES & Babies for more information about one type of non-IgE-mediated food allergy.

Will I pass allergies to baby in my breast milk?

Fortunately, allergies and Oral Allergy Syndrome (OAS) are not passed along to baby through breast milk. Concerns about potential food allergies should not discourage parents from offering breast milk, especially since breast milk offers a variety of nutritional and immune-supporting benefits for baby. Avoiding common food allergens either during pregnancy or when lactating hasn’t been shown to prevent food allergies.

If I am allergic to a food, how do I introduce that food to baby?

Rest assured that you are unlikely to experience a serious allergic reaction from simply being in the vicinity of your allergen or even from handling it. Most patients with food allergies react only upon ingestion. That said, there are steps you can take to minimize your risk of a reaction.

Lastly, try to stay calm, even if you are nervous at first. Children pick up on the feelings of the adults around them. With practice, offering your allergen to baby will get easier and become routine. If you feel very nervous, this is an excellent opportunity for a non-allergic parent, caregiver, relative, or friend to spend quality time with baby.

Can babies with cow’s milk allergy eat yogurt and cheese?

It depends. Cheese and yogurt contain the same allergenic proteins as cow’s milk, and they can trigger allergic reactions in sensitive babies. However, if a baby is not highly sensitive to casein (the heat-stable protein in milk), they may be able to tolerate cow’s milk, cheese, or yogurt fully baked in a biscuit, cake, or muffin. Some babies can also tolerate less extensively heated cow’s milk, cheese, or yogurt in fritters, pancakes, or waffles. However, this should be discussed with your healthcare professional before attempting it in the home setting. Check out Cow’s Milk for Babies & Toddlers to learn more.

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Written By

S. Bajowala, MD, FAAAAI. Board-Certified Allergist & Immunologist

V. Kalami, MNSP, RD, CSP, Board-Certified Pediatric Dietitian and Nutritionist

R. Ruiz, MD, FAAP. Board-Certified General Pediatrician & Pediatric Gastroenterologist

K. Rappaport, OTR/L, MS, SCFES, IBCLC, Feeding and Swallowing Specialist