Introducing Allergenic Foods to Your Baby

The advice on introducing allergenic foods has changed dramatically in recent years. We used to tell parents to delay allergens until age 2 or 3—now we know that early introduction actually REDUCES the risk of developing allergies. This shift in guidance has been life-changing for allergy prevention.

Understanding the current evidence-based recommendations helps you confidently introduce these important foods to your baby.

The New Science on Allergy Prevention AAP

Research has transformed how we think about food allergies.

What we used to believe:

• Delay allergenic foods to prevent allergies
• Wait until age 2-3 for peanuts
• Avoid allergens during pregnancy and breastfeeding
• These recommendations were NOT based on good evidence

What research now shows:

• Early introduction REDUCES allergy risk
• Delaying increases risk
• The LEAP study changed everything for peanut allergies
• Similar findings for other allergens

The turning point:

• LEAP study (2015): Early peanut introduction reduced peanut allergy by 81%
• This led to new guidelines worldwide
• The earlier, the better (within reason)

When to Start Introducing Allergens AAP

Timing is important but doesn't need to be complicated.

Current recommendations:

• Introduce allergenic foods around 4-6 months
• After baby has started some solid foods successfully
• Earlier introduction (4-6 months) is preferred for high-risk babies
• Don't delay past 6-12 months

What "high risk" means:

• Severe eczema
• Existing food allergy
• Family history of food allergies
• These babies benefit MOST from early introduction

Order of introduction:

• Start with a few non-allergenic foods first
• Then begin introducing allergens
• One new allergen at a time
• Space introductions by 2-3 days to identify reactions

The Major Allergenic Foods AAP

These foods cause most allergic reactions in children.

Top allergens to introduce:
1. Peanuts
2. Eggs
3. Cow's milk (in foods, not as drink before 1 year)
4. Tree nuts
5. Fish and shellfish
6. Wheat
7. Soy
8. Sesame (newly added to the list)

Priority allergens:

• Peanuts and eggs are particularly important to introduce early
• These show the strongest evidence for early introduction reducing risk
• Don't neglect the others—introduce all over time

How to Introduce Each Allergen AAP

Safe introduction methods for each major allergen.

Peanuts:

• Mix peanut butter with water to thin it (2 tsp PB + 2-3 tsp water)
• Or mix into purees or infant cereal
• Bamba puffs (peanut snacks) dissolve easily
• NEVER give whole peanuts or chunks (choking hazard)

Eggs:

• Start with well-cooked egg (scrambled, hard-boiled)
• Mash thoroughly
• Both yolk and white are allergenic
• Cook eggs thoroughly—don't give runny eggs

Dairy:

• Yogurt, cheese, butter in foods
• Not cow's milk as a drink before 1 year
• Well-tolerated by most babies
• Full-fat dairy is appropriate for babies

Tree nuts:

• Thinned nut butters (almond, cashew, etc.)
• Finely ground nuts mixed into foods
• NEVER whole nuts (choking hazard until age 4+)

Fish:

• Well-cooked, flaked fish
• Remove all bones
• Start with mild white fish
• Introduce different types over time

Wheat:

• Infant cereal
• Well-cooked pasta
• Soft bread
• Usually well-tolerated

Soy:

• Tofu (soft, mashed)
• Soy-based foods
• Often already in baby formula

Sesame:

• Tahini (sesame paste) mixed into foods
• Hummus
• Thinned like peanut butter

High-Risk Babies: Special Considerations AAP

Babies with severe eczema or existing allergies need extra care.

Who is high-risk:

• Severe eczema requiring prescription treatment
• Already has one food allergy
• Immediate family member with peanut allergy

What to do:

• Talk to your pediatrician before starting allergens
• May recommend testing before introduction
• Or supervised introduction in office
• Earlier introduction (4-6 months) is especially important

Testing considerations:

• Blood tests or skin prick tests can assess sensitization
• Positive test doesn't always mean allergy
• Negative test is reassuring
• Some providers recommend testing high-risk babies before peanut introduction

Safe Introduction Process AAP

How to actually do it safely.

First introduction:

• Give a small amount first (about 1/4 teaspoon)
• Wait and observe for 10-15 minutes
• If no reaction, give more
• Watch for 2 hours after eating

Watch for reactions:

• Hives or rash
• Swelling (face, lips, tongue)
• Vomiting
• Difficulty breathing (rare but serious)
• Fussiness or crying

What to do if reaction occurs:

• Stop the food
• For mild reactions: contact pediatrician
• For severe reactions (breathing problems, widespread hives, swelling): call 911
• Have Benadryl available (ask pediatrician about dosing beforehand)

When you can relax:

• After multiple successful exposures
• When baby has eaten the food many times without reaction
• Continue offering regularly to maintain tolerance

Maintaining Tolerance AAP

Introducing once isn't enough—ongoing exposure matters.

Why continued exposure is important:

• Tolerance needs to be maintained
• Stopping exposure may allow allergy to develop
• Regular inclusion in diet protects against allergy

How often:

• 2-3 times per week for each allergen
• Doesn't have to be large amounts
• Include in regular meals and snacks
• Make it part of normal eating

Practical strategies:

• Peanut butter on toast
• Eggs at breakfast
• Cheese as snacks
• Fish once a week
• Variety of nut butters

Allergic Reaction vs. Normal Response AAP

Know what's concerning vs. what's normal.

Normal (not concerning):

• Food on face causing mild redness (contact reaction)
• Minor spit-up
• Doesn't like the taste
• Mild gas

Allergic reactions:

• Hives (raised, itchy welts) especially away from where food touched
• Swelling of face, lips, eyes
• Vomiting (especially multiple times)
• Rash spreading beyond contact area
• Behavioral change (suddenly sleepy, inconsolable)

Severe reactions (call 911):

• Difficulty breathing, wheezing
• Swelling of throat or tongue
• Severe widespread hives
• Loss of consciousness
• Multiple symptoms at once

Common Questions AAP

Can I introduce multiple allergens at once?
Current guidelines say one at a time with 2-3 days between new ones. But once you've introduced several successfully, you can include multiple in the same meal.

What if there's a family history of allergies?
Family history increases risk but doesn't mean your baby will be allergic. Early introduction is even more important for these babies.

My baby has eczema. Should I delay allergens?
No—the opposite! Babies with eczema are at higher risk and benefit most from early introduction.

Do I need to see an allergist first?
Most babies can safely start allergens at home. High-risk babies (severe eczema, existing food allergy) should discuss with their pediatrician first.

What if my baby doesn't like a food?
Keep trying! It can take 10-15 exposures to accept a new food. Mix into foods they already like.

The Bottom Line

Early introduction of allergenic foods—starting around 4-6 months—significantly reduces your baby's risk of developing food allergies. Don't delay these important foods. Introduce them one at a time, watch for reactions, and then include them regularly in your baby's diet. AAP

Remember:

• Early introduction REDUCES allergy risk
• Start allergens around 4-6 months
• Introduce one at a time, 2-3 days apart
• Watch for reactions during and after eating
• Continue regular exposure to maintain tolerance

Clara is here when you have questions about introducing allergenic foods to your baby.