How to Safely Introduce Allergens When Starting Solids

It’s important to be informed about common allergens, how to safely introduce foods to your baby, and what to do if you think they’re having an allergic reaction.



An allergic reaction

to food occurs when the body’s immune system reacts to a harmless food, identifying it as dangerous. A reaction can vary from mild to severe and can occur with any food, however there are nine types of foods that cause the majority of reactions.

The foods that most commonly cause allergic reactions are:

  • Peanuts
  • Eggs
  • Fish
  • Tree nuts (almonds, Brazil nuts, cashews, chestnuts, hazelnuts, hickory nuts, macadamia nuts, pecans, pine nuts, pistachios and walnuts)
  • Shellfish
  • Soy
  • Cows’ milk
  • Wheat
  • Sesame seeds



It is recommended to introduce common food allergens around six months when you introduce other solid foods to your baby. Even babies who have a higher risk of developing allergies, either due to their family history or another condition, should be introduced to these foods. However, if you have concerns, it’s best to discuss with your GP. Research shows that delaying the introduction of allergy-causing foods does not prevent allergies, but that introducing these foods before your baby turns one can greatly reduce their risk of developing a food allergy. 

You can offer common allergy-causing foods one at a time to check for a reaction, ensuring your baby doesn’t have an allergy to that food before introducing something new. Once they have been introduced and if there has been no allergic reaction, it’s recommended to continue offering these foods regularly (approximately twice a week) to maintain your baby’s tolerance to them.



The symptoms of an allergic reaction to food can occur immediately or within two hours of ingestion, and can range from mild to severe.

Mild to moderate symptoms can include: 

  • Swelling of the lips, face or eyes
  • Rash, hives, or red welts on the skin
  • Red, watery eyes
  • Itchy mouth or throat
  • Vomiting
  • Diarrhoea

Severe symptoms (signs of anaphylaxis) are:

  • Difficulty breathing (noisy)
  • Swelling of the tongue
  • Coughing, wheezing, and shortness of breath
  • Baby becomes pale and floppy

If your baby is having a severe allergic reaction, call an ambulance immediately on 111. 

If you notice that your baby has had any mild to moderate symptoms of an allergic reaction, do not offer the food again. Book in to see your GP for an appointment and they will guide you on the next steps. If the food causing the reaction is unknown, you may be referred to a specialist for further testing and treatment.