What foods are the most likely to cause potential allergies?
The major food allergens include milk, egg, wheat, soy, peanut, tree nuts, fish, shellfish, and sesame. The most common food allergens for children are peanut and milk, with cow's milk the most common food allergen in early life.
What is the right approach for early introduction of these potential food allergens?
Fearing adverse reactions, many parents historically preferred to wait before introducing these potential food allergens to their kids. But that’s no longer the prevailing wisdom among experts. Doctors no longer believe that waiting until baby is older prevents food allergy. In fact, there is evidence that introduction to peanut in the first year of life can prevent the development of peanut allergy. Especially in infants who are at high risk of developing food allergy, the emphasis is now on early introduction of peanut and egg, rather than avoidance.
Typically, in babies without eczema or any food allergy, I recommend introducing age-appropriate allergenic foods in the first year of life in accordance with family preferences and cultural practices. I suggest prioritizing the introduction of peanut and egg, which has demonstrated evidence of benefit. There are currently no specific guidelines on order of egg and peanut introduction but it should be a shared decision made between parents and the baby’s doctor.
For babies with mild to moderate eczema, we recommend introducing peanut-containing foods at around 6 months of age. If your baby has severe eczema, you are concerned that he/she has an egg allergy and you have not yet introduced peanut, I recommend seeing an allergist as early as 4 to 6 months of age to determine if peanut should be introduced and, if so, the preferred method of introduction. If your baby has severe eczema and/or egg allergy, and you had already introduced peanut which he/she tolerates without any problem, please continue feeding your baby peanut to reduce the risk of peanut allergy once you start avoidance.
What is the best way to introduce these foods?
Once your baby has successfully eaten other solid foods (like single-grain cereals, followed by fruits, vegetables), you can begin to introduce allergenic foods in age-appropriate forms. That doesn’t mean Eggs Benedict or a PBJ sandwich, of course! Follow these tips for easy introduction of these tricky foods:
- Start with a small amount: just a spoonful or two of any allergenic food is enough to give baby a taste of the flavor and watch for potential allergic reaction.
- For peanut, the National Institute of Allergy and Infectious Diseases (NIAID) recommends infant-safe forms in the amount of 2 teaspoons, 3 times per week (for a total of 6 grams of peanut protein).
- To prevent choking in infants, try thinning peanut butter with water, milk, or pureed fruit. This dilution may be necessary until children are able to safely eat foods with the consistency of peanut butter spread thin—that can be after 12 months of age or based on individual developmental abilities.
- During the initial feeding period, serving single-ingredient foods, one at a time, is recommended to observe for symptoms of allergy. Once foods are tolerated, they can be combined.
- There is no evidence guiding how long a given food must be fed before moving on to the next new food. However, generally, when offering a potential food allergen, I advise parents to give baby an age-appropriate serving size at least 3 times over 3-5 days to confirm tolerance.
Recognizing allergic reactions in infants and toddlers can be challenging for not only parents and caregivers, but also providers, as your baby is unable to verbalize what they are feeling/experiencing when they are having an adverse food reaction. Behavior changes that may be noted during a reaction can include clinginess, fussiness, or inconsolability, but it is important to note that these behaviors alone may also be present in healthy infants not experiencing an allergic reaction.
Skin, gastrointestinal, and respiratory symptoms were most frequently reported in infants and toddlers, although symptoms involving other organ systems can also occur.
- The type of skin reaction may be “itching, rash, hives or swelling.” Please note the location of the skin reaction with respect to where the skin had contact with the allergen so we can determine if the reaction was the result of a topical contact reaction or a systemic reaction, the latter of which is more concerning. Please take pictures as they are worth a thousand words when you seek consultation with an allergist.
- The most common gastrointestinal symptom is vomiting, although diarrhea can also be considered a potential allergic symptom.
- Belly breathing, fast breathing, nasal flaring, chest or neck “tugging,” wheezing, hoarse voice, hoarse cry, and repetitive cough are all examples of respiratory symptoms.
Timing of the adverse reaction relative to when your baby consumed a potential culprit food is extremely essential, as there are different types of food-induced reactions including scenarios where administration of epinephrine, the first-line treatment of anaphylaxis (a severe life-threatening allergic reaction) is indicated. Diagnostic testing and management can be very different for each type of food-induced reactions; for example, skin testing and an epinephrine auto-injector prescription likely are not appropriate for food intolerances,and concerns that certain foods may exacerbate underlying eczema would warrant a separate discussion. I recommend keeping a food diary when you start to notice these reactions in your baby, particularly if they become recurrent so that you and your allergist can have a full conversation about how to proceed.
While introducing baby to allergenic foods can be a stressful experience, it is so important for their growth and development! The goals of early infant feeding are to introduce foods of varying flavors and textures to encourage future food preference, and to provide nutrition in a balanced and proportional manner for growth and development. Increasing the diversity of both food and food allergen intake in the first year of life is associated with a lower prevalence of food allergy—something all parents are hoping for.