Food Allergies in Babies: How to Introduce Allergens Safely

Food allergies are adverse immune reactions to proteins in certain foods. They affect 6-8 % of children under 3 in developed countries, and their prevalence has risen significantly in recent decades, prompting the scientific community to completely revise allergen-introduction guidelines.

The paradigm shift is clear: delaying allergen introduction does not protect against allergies; in many cases, it increases the risk. The LEAP (Learning Early About Peanut Allergy) and EAT (Enquiring About Tolerance) studies, published in The New England Journal of Medicine and The Journal of Allergy and Clinical Immunology, have transformed international guidelines, including those of the AAP and ESPGHAN.

Which Food Allergens Are Most Common in Children?

When and How Should Allergens Be Introduced?

The AAP and the ESPGHAN now recommend:

• Start from around 6 months, once complementary feeding has begun.
• Introduce common allergens early and regularly, rather than delaying them.
• One new allergen at a time, with 3 consecutive days of exposure before introducing the next.
• Offer in age-appropriate formats: smooth nut butters thinned with breast milk, well-cooked scrambled egg, yoghurt, etc.
• Continue regular exposure once tolerated: eating an allergen only once and then not again for weeks does not maintain tolerance.

Peanut: The LEAP Protocol

The landmark LEAP study (2015) showed that introducing peanut between 4 and 11 months reduced the risk of peanut allergy by 81 % in high-risk infants. The AAP recommends:

• High-risk babies (severe eczema and/or egg allergy): introduce peanut at around 6 months after allergy testing or a supervised first exposure.
• Moderate-risk babies (mild-moderate eczema): introduce peanut at around 6 months without prior testing.
• Low-risk babies (no eczema, no food allergies): introduce peanut freely with other solids.

Safe peanut formats for babies: smooth peanut butter thinned with warm water or breast milk; peanut puffs; Bamba snacks.

Egg

• Introduce well-cooked egg (both yolk and white) from 6 months.
• Start with small amounts (a quarter of a scrambled egg) and increase over days.
• Raw or lightly cooked egg should be avoided in infancy.

Cow's Milk Products

• Yoghurt and cheese can be introduced from 6 months as part of complementary feeding.
• Cow's milk as a main drink should wait until 12 months, though small amounts in cooking are fine from 6 months.

What Are the Signs of an Allergic Reaction?

If you suspect anaphylaxis, call emergency services immediately. The AAP recommends that families of children with known food allergies carry an adrenaline auto-injector (EpiPen) at all times.

What About Family History and High-Risk Babies?

Having a parent or sibling with food allergies, eczema, asthma or hay fever increases a baby's risk. However, the AAP emphasises that even high-risk babies should have allergens introduced early, as the LEAP study demonstrated that early introduction is precisely what reduces risk in this population.

Managing the Emotional Weight of Allergen Introduction

Introducing allergens can be anxiety-inducing, especially for parents with a family history of allergies. Disagreements about risk tolerance and how cautious to be are common in couples.

At LetsShine.app our AI mediator can help you and your partner talk through your concerns, align on a plan and manage the stress that comes with feeding decisions in those crucial first months.

Frequently Asked Questions

Should I avoid allergens during pregnancy or breastfeeding? No. The AAP and current evidence indicate that avoiding allergens during pregnancy or breastfeeding does not reduce the risk of allergies and may actually increase it. A varied maternal diet is recommended.

Can I introduce multiple allergens in the same week? Yes, as long as you separate each new allergen by 2-3 days to identify the cause of any reaction. There is no need to wait weeks between new allergens.

What if my baby has eczema -- should I delay allergens? The opposite. The AAP specifically recommends early allergen introduction for babies with eczema, as they are at higher risk and benefit most from early exposure.

Do allergen drops or patches work? Oral immunotherapy and epicutaneous (patch) therapy are being studied for treatment of established allergies, not for prevention. For prevention, the evidence supports early dietary introduction.