How to Introduce Allergens to Your Baby Without the Anxiety

This article is for general educational purposes and does not replace advice from your baby's healthcare professional. Always consult your GP, health visitor, or a paediatric allergist if you have specific concerns about your baby. Last reviewed: August 2026.

For many parents, allergen introduction is the part of starting solids that causes the most dread. What if there's a reaction? What if I do it wrong? What if I'm not near a hospital?

The anxiety is understandable. But the science is reassuring — and having a clear process makes all the difference. Here's exactly how to introduce allergens safely, calmly, and systematically.

In This Article

• Allergen Introduction: The Simple Version
• Why Early Allergen Introduction Matters
• Is My Baby Ready for Allergens?
• The 9 Allergens Commonly Prioritised When Introducing Solids
• The Step-by-Step Process
• Age-Appropriate Forms for Each Allergen
• Recognising a Reaction
• A Note on High-Risk Babies
• The Tracker That Takes the Guesswork Out
• Medical & Evidence Sources

Allergen Introduction: The Simple Version

• Around 6 months: Start when your baby is developmentally ready.
• One at a time: Introduce potentially allergenic foods individually.
• Small amount: Start with an age-appropriate portion.
• Watch: Stay with your baby and observe for symptoms.
• If tolerated: Keep the food in the regular diet.
• If severe symptoms occur: Treat as an emergency.

Why Early Allergen Introduction Matters

For years, parents were advised to delay introducing common allergens. That guidance has been reversed. Multiple large-scale studies — including the landmark LEAP trial on peanuts — have shown that early, regular introduction of allergens significantly reduces the risk of developing a food allergy.

Current guidance from paediatric allergy organisations in the UK, US, and Australia now recommends introducing allergens from around 6 months, alongside other first foods — not after them. [ASCIA]

Is My Baby Ready for Allergens?

Six months is a general guide, not an automatic green light. Your baby should generally show signs of developmental readiness for complementary foods, including being able to: [CDC]

• Sit upright with support
• Control their head and neck
• Open their mouth for food
• Swallow rather than repeatedly push food out
• Bring objects toward their mouth

If you're unsure whether your baby is ready, speak with your health visitor or GP before starting.

The 9 Allergens Commonly Prioritised When Introducing Solids

The following foods are commonly prioritised during allergen introduction because they account for the majority of food allergic reactions in infants. Note that different countries and health bodies may list additional allergenic foods — such as celery, mustard, and sulphur dioxide — so this list is a practical starting point, not an exhaustive one. [NHS]

1. Peanuts
2. Tree nuts (cashew, walnut, almond, etc.)
3. Eggs
4. Cow's milk (dairy)
5. Wheat
6. Soy
7. Fish
8. Shellfish
9. Sesame

Each one should be introduced individually, in an age-appropriate form, and tracked carefully.

Want a simple way to log every introduction? The Baby Allergen Introduction Tracker is a dedicated printable workbook — one row per allergen, with space for date, amount, and any observations. Download it here →

The Step-by-Step Process

Step 1: Choose the right time of day

Introduce a new allergen in the morning or early afternoon — never at bedtime. This gives you several hours to observe your baby for any reaction while you're alert and able to act if needed.

Step 2: Start with a small amount

Begin with a tiny portion — a quarter teaspoon or less. If there's no reaction after 10–15 minutes, you can offer a little more at the same sitting. There's no need to build up over days for the first exposure; a small taste is enough to start.

Step 3: Introduce one new allergen at a time

Introduce allergenic foods one at a time so that if a reaction does occur, you can clearly identify the cause. While you're waiting to introduce the next new allergen, continue offering any previously tolerated foods as part of your baby's usual meals — there's no need to pause those. [NHS]

Many families find it helpful to wait a few days between introducing each new allergen. This is a practical approach, not a strict medical rule — the key principle is introducing them individually, not all at once.

Step 4: Keep offering it regularly

Once a food is confirmed safe, keep offering it regularly as part of your baby's usual diet. Early introduction only reduces allergy risk if the food continues to be part of the diet. [ASCIA]

Step 5: Log everything

Keep a simple record of what you introduced, when, how much, and any observations. This is invaluable if you ever need to speak to a GP or paediatric allergist. The Baby Allergen Introduction Tracker is designed exactly for this — a structured log for all 9 allergens, with space for date, amount, reaction notes, and a repeat-exposure tracker to help you stay consistent once a food is tolerated. Download it here →

Age-Appropriate Forms for Each Allergen

Whole nuts and large pieces of fish are choking hazards. Here's how to offer each allergen safely at around 6 months: [NHS — Foods to avoid giving babies]

• Peanuts: Smooth peanut butter thinned with breast milk, formula, or water and spread onto a food — never offered as a thick spoonful by itself, and never as whole peanuts
• Tree nuts: Finely ground almond or cashew mixed into purée or yoghurt
• Eggs: Well-cooked scrambled egg or hard-boiled egg mashed into purée
• Dairy: Full-fat plain yoghurt or soft cheese (cow's milk as a drink is not recommended before 12 months, but dairy in food is fine)
• Wheat: Soft-cooked pasta, bread soaked in soup or sauce, or wheat-based baby cereal
• Soy: Tofu (soft, mashed) or soy-based baby cereal
• Fish: Well-cooked, flaked white fish (check carefully for bones)
• Shellfish: Well-cooked, finely minced prawn or crab — never raw or lightly cooked shellfish
• Sesame: Tahini thinned with water or mixed into purée

Recognising a Reaction

Allergic reactions can range from mild to life-threatening. Knowing the warning signs helps you recognise when to monitor, when to seek medical advice, and when to treat an emergency. [NHS]

For mild or moderate symptoms, monitor your baby closely and contact your GP. For any signs of anaphylaxis, treat it as a medical emergency: if your baby has a prescribed adrenaline/epinephrine auto-injector, use it according to their emergency action plan and call your local emergency medical services immediately. [ASCIA]

The Baby Food Starter Guide includes an Emergency Quick-Reference Card covering both choking and allergic reaction responses.

What's NOT a reaction:

• A red ring around the mouth (often from acidic foods like tomato or citrus)
• A single change in stool consistency, which can happen when babies start new foods — however, repeated vomiting, significant diarrhoea, or symptoms occurring consistently after a particular food should be discussed with a healthcare professional
• Spitting the food out or making a face

A Note on High-Risk Babies

Babies with severe eczema, an existing food allergy, or other significant allergy risk factors may need an individualised plan. Speak with your baby's doctor or an allergy specialist before introducing peanut or another high-risk allergen if you're concerned. [NIAID] Current guidance generally supports introducing allergenic foods around six months even for higher-risk infants — but with appropriate medical guidance in place.

The Tracker That Takes the Guesswork Out

The hardest part of allergen introduction isn't the introduction itself — it's keeping track. Which ones have you done? When did you last offer peanut butter? Did you log that egg introduction last Tuesday?

The Baby Allergen Introduction Tracker is a dedicated printable workbook built specifically for this. It gives you:

• A structured log for all 9 priority allergens
• Space to record the date introduced, amount given, and any observations
• A repeat-exposure tracker so you don't lose track of which foods need to stay in rotation
• A calm, clear format you can fill in at the table — not scramble to reconstruct from memory

Work through the 9 allergens with a clear plan — not a knot in your stomach.

Download the Baby Allergen Introduction Tracker →

Medical & Evidence Sources

• NHS — Food allergies in babies and young children
• NHS — Foods to avoid giving babies and young children
• CDC — When, What, and How to Introduce Solid Foods
• NIAID — Addendum Guidelines for the Prevention of Peanut Allergy
• ASCIA — Infant Feeding and Allergy Prevention
• Du Toit G, et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy (LEAP Trial). N Engl J Med. 2015;372:803–813.