How to Introduce Babies to Allergens

Listen to Season 2, Episode 1 above or on Apple Podcasts or Spotify​

When thinking about the introduction of allergens to your little ones, it was previously recommended to delay until two, even three years of age. However, new evidence from ASCIA (Australian Society of Clinical Immunology & Allergy), shows that this was probably doing more harm than good, leading to the rising incidence of allergies in children. 

Consequently, the current recommendations now state that all allergens should be introduced by the time your child is eleven months old, even if your child is considered high risk (ie. severe eczema or immediate family history of allergies).

Introducing allergens

It is recommended that solids should be introduced around six months of age, but not before four months of age, being mindful of your child is showing signs of readiness. The keys signs that your little one is ready to start solids are:

• The ability to hold their neck upright

• Showing an interest in food

• Reaching for food while you eat

• Opening their mouth when you bring a spoon near. 

Once solids have been introduced, it is also appropriate to commence allergen introduction, by introducing one at a time. It is advised that eggs should be one of the allergens introduced.

How to introduce allergens?

The best way to introduce an allergen is to start with a small amount (1/4 teaspoon) mixed into a puree which your baby has previously accepted. For example, in the case of eggs, you would hard boil an egg and then mash then add ¼ teaspoon of mashed egg into a previously tried puree, such as pumpkin.

On the following day, increase the amount of egg to ½ teaspoon, and then 1 teaspoon on the third day.

It may come as a surprise to hear that allergic reactions often don’t occur on the first exposure. It will often be the second or third exposure to a certain food, therefore it is important your baby tries new foods, particularly the allergens, for 3 days before moving onto another one.

Once an allergen is accepted and tolerated, it should be included regularly (at least twice per week) as part of baby’s diet.

When introducing nuts, it is best done in the form of a smooth nut butter, nut powder or where possible a nut flour e.g. Almond flour/meal.

What are the key food allergens?

While many different foods can cause allergies, there are foods considered to be common allergens, due to the high incidence in which they occur. The foods below make up approximately 90% of all allergies.

The eight most common allergens are:

• Cow’s Milk Protein Allergy (CMPA). It is important to note that a CMPA is different to a lactose intolerance

• Eggs

• Peanuts

• Tree nuts (including sesame seeds)

• Soy

• Wheat

• Gluten

• Fish/Shellfish

Under food labelling laws in Australia, these common allergens always have to be declared on food labels and will often appear in bold in the ingredient list.

Allergies in children

When it comes to allergies, unfortunately we still do not know what ultimately causes them, or why one child in a family, for example, will develop one and another may not. There are thought to be some genetic factors, so a child with one or two parents who have an allergy would be considered a moderate risk (1 parent with an allergy) to high risk (both parents have allergies).

The good news is that many children will outgrow allergies, particularly allergies to eggs and cow’s milk, which are the most common allergies in children aged 1 to 3.

Allergies vs Intolerances

While allergies and intolerances can have some similar symptoms, they are distinctly different. An allergy is defined by an immune response, whereby the body mistakenly identifies a specific food or something in the food (usually the food protein) as harmful. As a means of defending the body, the immune system goes into overdrive and releases an antibody called immunoglobulin E (IgE) to neutralise the allergen.

On subsequent intakes of that food, the now sensitised antibody senses the presence of that food and triggers the release of chemicals, such as histamine, which cause the symptoms such as swelling, difficulty breathing, rashes, hives, vomiting etc.

In the most severe cases, allergic reactions can be life threatening, which is a condition known as anaphylaxis.

Intolerances, unlike allergies do not result in an immune response and are much less severe. They usually occur when the body is not able to digest a particular food, such as lactose in milk, or when a particular food irritates the digestive system. The symptoms of a food intolerance are usually linked to the digestive system and include nausea, stomach cramps, diarrhoea and flatulence, as well as headaches and irritability.

What to do if your child has a suspected food allergy?

If you suspect your child has a food allergy, make an appointment with your GP, and if you suspect a certain food, remove that food from the diet. You can try providing a ‘challenge’ (whereby you give baby some of the offending food) in front of the GP so they can assist in clarifying if it is or is not a true allergy.

The next steps would be a referral to a specialised allergy clinic where further testing can take place, however this is likely to only take place if the child is over the age of two. It can also be useful to keep a food diary and symptom diary, which can be shown to the allergist if and when you see them.

Unfortunately, there is no cure for allergies, however once an allergy is identified, it can be managed with the help of an allergist and also a dietitian who will provide suitable dietary substitutions to ensure nutritional requirements are met.

What are common allergy symptoms?

Allergies usually result in a somewhat immediate effect with symptoms likely to occur anywhere from five minutes to two hours after the offending food is ingested. Symptoms will also vary in severity from person to person.

The most common symptoms to look out for:

• Eyes

  – itching, watering

• Nose

  – stuffiness, sneezing, running

• Mouth

  – itching, swelling

• Throat

  – swelling

• Digestive system

  – stomach pains, vomiting, diarrhoea

• Skin

  – rashes, such as hives (urticaria), welts or atopic dermatitis

• Lungs

  – wheeze, cough, asthma (more common in children than adults)

• Central nervous system

  – headache, irritability, fatigue, convulsions.

What not to do when introducing allergens

• Do not introduce new foods before bed time. A new food or allergen should be introduced in the first half of the day, ideally after a nap so you can observe for any adverse reactions.

• Do not introduce new food or allergens when you are far away from emergency services. In the rare case of a severe allergic reaction, you want to be able to reach the hospital as soon as possible.

• Do not hold nut parties on the hospital lawns – where a group of you (say your mother’s group) introduces nuts to all of your children at the same time.

• Do not withhold introduction of allergens beyond 1 year (unless there is a special medical reason).

Testing for Allergies

The gold standard for testing for allergies is a Skin Prick Test (SPT). Once one allergy is suspected, they will usually test for a number of other allergies. Skin Prick Testing involves a series of tiny pricks being made in the skin (usually arm or back) and allergen extracts being applied to the skin pricks.

A small itchy lump called a wheal surrounded by a red flare will usually appear. The size of the wheal will be measured against a control. If SPT is contraindicated or can’t be achieved (for example if a baby’s eczema was particularly bad), a blood test for allergen specific antibodies could be carried out. This however, is not the preferred option, as it is not as specific.

When it comes to the accuracy of the results, it is not as straightforward, as the severity of reactions can vary from child to child. In addition, the way the test is carried out and interpreted can also yield different results.

SPT results should be carefully interpreted by an experienced allergist, taking into account the patient’s other clinical history. The allergist will then work with the family to develop an appropriate allergy management plan.

While there are no strict age limits for Skin Prick Testing (SPT), skin reactions are often diminished as infants often show larger flares due to their sensitive skin and smaller wheals. As a result of the increased risk of testing and greater complexity of interpretation, it is not commonplace for a child under the age of two years to take part in a Skin Prick Test. It would only be if allergy was strongly suspected.

Allergy resources:

Milk allergies

ASCIA - Australian society of clinical immunology and allergy

Prevent allergies

Download the episode transcript here.This article was written by Olivia Bates, founder of Nourishing Bubs, in conjunction with Season two, episode x of Purebaby’s podcast, Pure Parenthood. Olivia is a Dietician, with a Bachelor of Nutrition & Dietetics and a Certificate in Paediatric Nutrition.

To learn more about Nourishing Bubs, visit their website or Instagram.