Introducing allergenic foods: the European approach

6-9 months · Feeding · Reviewed 20 June 2026 · All articles

For years, parents were told to delay highly allergenic foods - peanuts, egg, fish, wheat - until well into the second year of life, in the hope that an older immune system would be less likely to react. That advice has changed substantially. The current evidence, reflected in guidance from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the NHS, points in the opposite direction: introducing allergenic foods early, alongside the start of complementary feeding, appears to reduce rather than increase allergy risk.

This article explains what ESPGHAN's 2017 complementary feeding guidance says about allergen introduction, what it means practically for families, and how to approach the first exposures with confidence.

What ESPGHAN 2017 says

The ESPGHAN 2017 position paper on complementary feeding marked a significant shift in European guidance. Based on a systematic review of available evidence, the committee concluded that there is no convincing scientific evidence that avoiding or delaying the introduction of allergenic foods - either during pregnancy, breastfeeding, or the weaning period - reduces the risk of allergy in either low-risk or high-risk infants.

Importantly, ESPGHAN noted emerging evidence that early introduction of allergenic foods, particularly peanut and egg, when introduced alongside continued breastfeeding, may actually decrease the risk of developing allergy to those foods. The committee recommended that allergenic foods should not be avoided and should be introduced as part of normal complementary feeding from around four to six months of age, when the infant shows developmental readiness for solid foods.

The guidance covers the major food allergens: cows' milk and dairy products, egg, peanut, tree nuts (such as almonds, cashews, walnuts), wheat and other gluten-containing grains, soy, fish, shellfish, and sesame. These fourteen foods account for the large majority of food allergies in children in Europe.

ESPGHAN also noted that the timing of gluten introduction in particular had been extensively studied. Earlier guidance had suggested a narrow window for gluten introduction to reduce coeliac disease risk, but the 2017 guidance concluded that there is no evidence to support this and that gluten can be introduced at any time within the window of starting complementary feeding, whether the infant is breastfed or formula-fed.

Timing and developmental readiness

ESPGHAN recommends starting complementary feeding no earlier than 17 weeks (approximately four months) and no later than 26 weeks (six months). Most infants show signs of readiness around six months: they can hold their head steady, sit with support, show interest in food, and have lost the tongue-thrust reflex that causes younger babies to push food back out of their mouths.

Allergenic foods can be introduced from the same point as other complementary foods. There is no benefit to holding them back while other foods are established first. The NHS guidance echoes this, recommending that from around six months, babies can try a wide range of foods including allergenic ones, alongside first tastes of vegetables, fruits and cereals.

Both ESPGHAN and the NHS recommend breastfeeding continues alongside the introduction of solid foods. There is some evidence that continued breastfeeding during allergen introduction may provide a protective effect, though the evidence is not strong enough to be stated as a requirement. Formula-fed infants should still have allergenic foods introduced early and in the same way.

The EFSA (European Food Safety Authority) scientific opinion on allergen thresholds and labelling has informed European food regulation, and families feeding babies commercially prepared foods should be aware that ingredient labelling requirements mean allergens must be clearly listed. However, home-prepared foods are the recommended starting point for most weaning, as they give full control over ingredients and portion sizes.

How to introduce allergenic foods in practice

The practical approach recommended by the NHS and consistent with ESPGHAN guidance is to introduce one new allergenic food at a time, with a gap of two to three days before introducing the next. This means that if a reaction occurs, you can clearly identify which food caused it. It is not necessary to introduce foods in a specific sequence, but having a plan and working through the list systematically is a sensible approach.

New allergenic foods should be given at home rather than at nursery, at a meal where you will be present for the following two to three hours. Give the first exposure in the morning or at lunchtime rather than just before bedtime, so you are alert to any reaction. Start with a small amount - a quarter of a teaspoon or less - and increase gradually over subsequent servings if no reaction occurs.

Peanut is often the allergen parents are most anxious about, partly because peanut allergy can cause severe reactions and tends to persist into adulthood. For low-risk infants (those without severe eczema or known egg allergy), ESPGHAN guidance and NHS guidance agree that peanut should be introduced as part of normal complementary feeding from around six months. Peanut butter is the most practical form - smooth, not crunchy, and well thinned with a little water, breastmilk or formula. Whole peanuts are a choking hazard and should never be given to young children.

Egg can be introduced as well-cooked scrambled egg or hard-boiled egg mashed into puree. Lightly cooked or raw egg (such as soft-boiled) should be avoided in infants, both because of allergy risk and because of salmonella risk. Fish can be given as flaked white fish or salmon blended into vegetable puree. Wheat is typically introduced through small amounts of bread, pasta, or baby cereal.

High-risk infants and when to seek advice first

ESPGHAN's guidance on early allergen introduction applies broadly, but there are specific circumstances where it is important to seek advice from your GP or paediatrician before introducing certain foods at home.

Infants with severe or poorly controlled eczema (as assessed by a health professional, not just mild dry skin or small patches) are at higher risk of peanut allergy. For these infants, the LEAP (Learning Early About Peanut allergy) study and subsequent guidance from allergy specialists recommends an assessment for peanut allergy - using a skin prick test or blood test - before home introduction, and potentially a supervised oral food challenge. The NHS England guidance on peanut introduction for high-risk infants outlines when a referral to an allergy specialist is appropriate.

Infants who have already had a reaction to egg, whether diagnosed or suspected, should also have medical guidance before peanut is introduced, as the two allergies often co-occur. Similarly, any infant who has had a previous anaphylactic reaction to any food should be managed by a paediatric allergy team before further allergen introductions.

For the majority of healthy infants without severe eczema or known food allergy, home introduction of allergenic foods starting from around six months is safe and recommended. The anxiety that many parents feel about this process is understandable, but the weight of current evidence firmly supports early introduction over avoidance or delay.

Maintaining exposure over time

Introducing an allergenic food once is not sufficient. ESPGHAN and NHS guidance both note that to maintain tolerance, allergenic foods should be kept in the diet regularly once introduced. Giving peanut, egg, or fish only once and then not again for months may not sustain the immune tolerance that early introduction is thought to promote.

Practically, this means including foods like egg and dairy in the diet multiple times per week once they have been safely introduced. Peanut butter on toast or in porridge a few times per week, egg at breakfast or lunch regularly, and fish once or twice per week are realistic targets that fit into normal family meals and help ensure continued exposure.

If a food has been introduced and then accidentally excluded from the diet for an extended period, it is generally safe to reintroduce it at home starting with a small amount again, unless a reaction was ever observed, in which case medical advice should be sought before retrying.

Frequently asked questions

When should I start introducing allergenic foods?

ESPGHAN 2017 guidance recommends introducing allergenic foods from around four to six months of age, which coincides with the start of complementary feeding. There is no evidence that delaying allergenic foods beyond six months reduces allergy risk - in fact, early introduction alongside continued breastfeeding may reduce it. Always introduce new allergenic foods at home, one at a time, during the daytime, so you can watch for any reaction.

Do I need to introduce allergens in a specific order?

No specific order is required. ESPGHAN guidance suggests introducing different allergenic foods one at a time, with a gap of a few days between each new food, so that if a reaction occurs you can identify the cause. Common allergenic foods include cows' milk products, egg, peanut, tree nuts, wheat, fish, shellfish, and sesame. Your health visitor or paediatrician can advise on a practical sequence.

Should I delay allergens if there is a family history of allergy?

ESPGHAN 2017 and the NHS both advise against delaying the introduction of allergenic foods even when there is a family history of allergy or eczema. Deliberate avoidance has not been shown to prevent allergy development and may actually increase risk. If your baby has severe eczema or a known egg allergy, speak to your GP or paediatrician before introducing peanut, as specific supervised protocols may apply.

What counts as an allergic reaction and what should I do?

Mild reactions can include hives, a rash around the mouth, or mild swelling of the lips. More serious reactions - difficulty breathing, significant facial swelling, persistent vomiting, or loss of consciousness - are signs of anaphylaxis and require an immediate emergency call. For any suspected allergic reaction, stop giving the food and contact your GP. For signs of anaphylaxis, call 999 or your local emergency number immediately.

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