Introducing Allergens to Babies: What Parents Need to Know

For many years, parents were advised to delay the introduction of common allergens like peanuts and eggs. The evidence has shifted significantly and current guidance now recommends introducing allergens early and regularly to actually reduce the risk of allergy developing.

What changed?

The LEAP study, a landmark trial published in 2015, showed that babies with eczema or egg allergy who were introduced to peanuts early (between 4 and 11 months) had an 80% lower risk of developing peanut allergy compared to those who avoided peanuts. This changed guidance across the world.

When to introduce allergens

Current guidance recommends introducing allergenic foods from around 6 months, alongside the introduction of other solid foods. If your baby has severe eczema or an existing egg allergy, speak to your GP before introducing peanuts or other high-risk allergens at home.

The nine major allergens to introduce

1. Peanuts (as smooth peanut butter thinned with water or baby food) 2. Tree nuts (almond, cashew, walnut — thinned or ground) 3. Eggs (well-cooked scrambled egg or hard-boiled) 4. Milk (cheese, yoghurt, cooked in foods — not as a main drink under 12 months) 5. Wheat (bread, pasta, crackers) 6. Soy (tofu, edamame, soy yoghurt) 7. Fish (well-cooked, boneless) 8. Shellfish (well-cooked shrimp, crab) 9. Sesame (tahini or sesame seeds)

How to introduce each allergen

Introduce one new allergen at a time, and wait 2 to 3 days before introducing another. This allows you to identify the cause if a reaction occurs.

Offer a small amount with a soft spoon and watch for signs of an allergic reaction over the next 30 to 60 minutes: hives, swelling around the mouth, vomiting, wheeziness, or a change in colour or energy level. Mild reactions like a small rash around the mouth are common and often not a sign of true allergy.

Call emergency services if baby shows signs of anaphylaxis: difficulty breathing, significant swelling of the face or throat, or sudden loss of consciousness.

Once they have tolerated it

Once your baby has tolerated an allergen without a reaction, continue offering it regularly, ideally two to three times per week. Regular exposure is what maintains tolerance.

Products designed for allergen introduction

Purpose-formulated allergen introduction products can make the process easier and more structured.