How to wean a baby with allergies

The importance of feeding is part of human life from the day we are born.

For the first few months, babies are only able to taste sweet and sour, leading to their first choice favouring the sweet taste of their mother’s milk. Eventually, at around 6 months, the taste buds develop further. The baby’s palate becomes more sensitive, not only to tastes but also to textures.

The first, and most nutritionally complete, food will be breastmilk or, for those who can’t or choose not to breastfeed, it will be formula milk. This will carry on until around 6 months of age, at which point solids should be introduced.

Why is there such a need to change to solids and decrease the need for milk? That need is mainly, but not only, for growth associated nutritional needs, but also focused on allergy prevention. 

But weaning – and the age that is introduced – is not just influenced by those needs, but by a wide variety of beliefs, personal choices, historical background and the need to go back to work (with the latter being the most comparable difference between the developed and underdeveloped world)

Past advice on Starting Solids

In the first two decades of the 20^th Century, children were not offered solids until their first year, as it was thought it could harm the child. In contrast, soon after that, the advice was reversed and children were then offered solids, including meat and liver, in the first two weeks of life. Cereals were to follow, and between 6 and 9 months of age, vegetables should be given.

It is important to note the role of baby formula has, even now, as there is a significant decrease in breastfeeding after the first month of life. This might also be the reason so many mothers decide to start weaning at an earlier age [Table 1].

Though solids have been given from very early stages in babies’ lives, there is not so much emphasis on its discussion, apart from more recent studies, which show the variations mainly in the 20^th Century [Table 2].

However, we have a better understanding of certain habits that still keep going up to now.

Current weaning advice:

There is much dispute around the age at which weaning should start. One of the reasons being gut maturity.

There has been some media attention on a piece of research in JAMA paediatrics that implied that babies who have solids introduced before 6 months sleep better. UNICEF has looked at this research and they have released a statement identifying weaknesses in this research, in particular potential bias in reporting. They continue to recommend that solids are not introduced until 6 months.

UNICEF also states SACN (Scientific Advisory Committee on Nutrition) which says that “introducing solid foods before four months is associated with increased risk of gastrointestinal, respiratory and ear infections in infants” and, as such, continues to advise solids are not introduced until 6 months.

Unfortunately, both UNICEF and SACN have disregarded current advice, suggesting allergens should be introduced from 4 months of age, with the suggestion that 3 months would also be protective against the development of allergies.

So is this good advice? Let’s consider the evidence.

Evidence:

• LEAP – Of the children who avoided peanut, 17% developed peanut allergy by the age of 5 years. Remarkably, only 3% of the children who were randomized to eating the peanut snack developed allergy by age 5. Therefore, in high-risk infants, sustained consumption of peanuts beginning in the first 11 months of life was highly effective in preventing the development of peanut allergy.
• EAT – The EAT Study has found that introducing allergenic foods into the infant diet from three months may be effective in food allergy prevention when sufficient amounts of allergenic foods are consumed. The study found that the prevention of a food allergy could be achieved with weekly consumption of small amounts of allergenic food. This means about 1½ teaspoons of peanut butter and one small boiled egg.
• LEAP-ON – After 12 months of peanut avoidance, only 4.8% of the original peanut consumers were found to be allergic, compared to 18.6% of the original peanut avoiders, a highly significant difference.
• The Government’s own Infant Feeding Survey shows 51% of infants were reported to have received solid foods before 4 months of age. This figure is consistent with the average age of introduction of solids in the Millennium Cohort Study which was 3.8 months.
• One reason put forward for not introducing solids before six months is concern about an increased risk of gastrointestinal infections. However, the Millennium Cohort Study recently found that the age of introduction of solids had no effect on the risk of hospitalisation for diarrhoea or lower respiratory tract infection.

So where do we stand on weaning?

• You should follow the current recommendation of introducing solids at 6 months of age.
• Children whose older siblings have a food allergy are not at higher risk of developing allergies. They should follow the same advice.

With the following exceptions, when it should be introduced at 4 months of age:

• Infants and young children with a family history of atopy, as they are at high risk for developing allergic disease.
• Those with a personal history of atopy, particularly those with moderate-to-severe eczema, are also at increased risk of developing other atopic diseases including food allergies.
• Infants who already have a food allergy.

Weaning Babies with Eczema

If the child has eczema, allergens should only be introduced if the eczema is under control. However, introduction should be delayed and the child referred to a specialist in the following circumstances. The main reason for this is so any skin reactions can be seen and associated with the food being taken:

• The eczema is uncontrolled.
• Needs 1% Hydrocortisone more often than once a day for 6 weeks.
• Needs a stronger steroid more than once.

Most importantly, if a child has passed the age of 4-6 months and no allergens have been introduced, you should do it at once and do not delay any further.

They should only be seen by an allergist if there is a history of reactions to a particular food. In this case, they should be tested and eventually be guided by an allergy dietitian. For the same reason, there is no need for most children to be seen by a dietitian before weaning.

Which foods to introduce first and how to do it?

Following several studies, the foods/allergens that should be chosen first are peanut and egg. Those had the highest evidence so far.

Next, you can give wheat, sesame (other seeds included) and fish (white and red fish, but seafood can also be included).

No specific studies were done for tree nuts, though the suggestion would be to introduce them after wheat, sesame and fish.

Next, let’s take a look at the best way to introduce allergens:

• Peanuts – use smooth peanut butter, puffed peanut sacks (if under 7 months they should be diluted in water or milk) or grind whole peanuts into a fine powder. It can be mixed into any pureed food the child has already eaten, yoghurts or baby porridge.
• Eggs – either scrambled eggs, omelettes, soft or hardboiled egg. This can be mixed into any pureed food the child has already eaten, yoghurts or baby porridge.
• Sesame or other seeds – hummus, finely ground seeds mixed into any pureed food the child has already eaten, yoghurts or baby porridge.
• Wheat – Weetabix or similar cereal, well cooked pasta, toast fingers or couscous.
• Fish or seafood – very well cooked and mashed. It can either be eaten on its own or mixed into any pureed food the child has already eaten.
• Tree nuts – finely ground and mixed into any pureed food the child has already eaten, yoghurts or baby porridge. If you find a butter, you can also use it.
• Milk – sugar free yoghurt, fromage frais or whole milk mixed in porridge or mashed potato. This should only be from around 7 months of age (though it was introduced earlier in the EAT study).

Weaning Warnings:

The initial dose should be roughly ⅛ or ¼ of a normal dose, followed by increased doses starting the next day.

Once safely introduced, the aim would be to have that allergen at least once per week.

You should not introduce more than one new allergen at a time. As there is a potential risk (though extremely small) that a delayed reaction can occur more than 24 hours later, it would be safe to say that a new allergen can be safely introduced 3 days after the previous one.

If at any point you suspect an allergic reaction, stop giving that food immediately, give anti-histamines and/or call the emergency services. In this case, your child needs a referral to the allergy services so he/she can be tested. Eventually, you may need to do either a food challenge or a careful reintroduction of the allergen at home again.