Brayden is a 3 year old boy who has been referred to your clinic following one occasion where he developed some facial swelling and wheeze after ingesting peanuts. Brayden’s allergy has been confirmed on skin prick testing. Brayden’s mum is pregnant, and is wondering how to prevent her second child from having a food allergy.
Allergy prevention (with strong family history of allergies) can be with breastfeeding, or use of a partially hydrolysed formula.
- Mothers should breastfeed for at least 6 months, and should not exclude potentially allergenic foods from maternal diet. They should continue to breastfeed while introducing new foods.
- Introduce solids at 4-6 months of age, when developmentally ready.
- Add a new food every 2-3 days to allow for observation of adverse food reactions.
- Do not delay introduction of potentially allergenic foods.
- If there is an adverse food reaction – avoid the food and seek medical advice. Continue introducing other new foods.
- Educate families about cross contamination, food education e.g. ingredients, always read food labels, travel action plan, eating out/alcohol/parties higher risk.
In infants with IgE-mediated food allergy:
Breastfeeding is preferred over formula feeding. Anaphylaxis from maternal allergen ingestion is rare. Usually it is not required to have maternal exclusion of food allergens, although patients can have trial of maternal dietary exclusion. If symptoms improve with trial, consider food challenge through maternal diet.
When breast feeding is not possible or when supplementary feeding needed, formula feeding can be commenced. Or when symptoms persist in an infant despite maternal dietary exclusion of cow’s milk protein and soy protein, then formula can be commenced.
In infants with cow’s milk allergy:
If there is cow’s milk anaphylaxis – can breastfeed, with no need for routine maternal dietary exclusion
If formula is indicated, use AAF – there should be immunologist review and soy challenge. Patients can then use soy if tolerated, or AAF if soy is not tolerated.
In cow’s milk allergy (not anaphylaxis) – eHF if <6 months, or soy if >6 months and tolerated.
Preparations we do not recommend:
- Cow’s milk based including anti-reflux and lactose free cow’s milk based formula
- Other mammalian milks e.g. goats milk
- A2 cow’s milk
- Rice drink
- Oat drink
- Soy drink
- Almond or other nut drinks
- Home-made cereal/soy/nut drinks
After infancy, there should be dietician review to determine the most appropriate option for dietary needs and calcium supplementation if required.
And finally, what does the future hold regarding immunotherapy for food allergies?
This has a research basis only – oral immunotherapy and sublingual immunotherapy are the most often studied. Subcutaneous (highest risk of anaphylaxis, affects safety profile), epicutaneous (preliminary reports promising).
Oral: highly effective but results for clinical tolerance after ceasing therapy are disappointing. Thus requires ongoing therapy to maintain tolerance. Nevertheless, the rate of acquisition of tolerance is higher than that seen in those patients who avoid the allergen. Allergens studied include cow’s milk, egg white, fish, apple, orange, celery and peanut.
Sublingual: efficacy lower than oral but better safety profile.
There is no role for immunotherapy in food intolerance or adverse reactions to food chemicals, additives, preservatives, artificial colours.