Prevention of Food Allergies

Mary Grace Baker, MD, allergist and pediatrician at the Icahn School of Medicine at Mount Sinai in New York City, describes the challenge of preventing food allergies in the first year of life as a race.

The strategy of introducing peanuts early has been the best studied, with the LEAP trial demonstrating that administering small doses of peanuts at age 4-11 months is highly effective in preventing peanut allergies. Other studies have found similar results for early introduction of milk products (typically starting with yogurt or cheese and not liquid cow’s milk) and cooked eggs.

But should every kid start getting a daily dose of peanut butter that early in life? Many parents do not seem to think so — and reports of peanut feedings gone dangerously bad fill social media accounts. The decision should be based on whether the infant is at high risk for food allergies.

Baker listed the main risks as moderate-to-severe atopic dermatitis, a first-degree family member with an immunoglobulin E (IgE)-mediated food allergy, and signs of egg sensitivity. 

The urgency for early introduction is critical in babies with moderate-to-severe eczema. “Household dust has meaningful amounts of peanut [and other food allergens] in it,” Baker said. “When an infant with a lot of cutaneous inflammation is specifically exposed to food in their environment, that exposure through inflamed skin is very pro-allergy.” In contrast, consuming a potential allergen by mouth and passing it through the gut tends to promote tolerance.

Pediatric providers can perform this allergy risk assessment at 4-6 months, when they typically assess the infant’s general readiness for starting solid foods. They should also address whether infants need allergy testing first.

Specifically for peanuts, the National Institute of Allergy and Infectious Diseases addendum guidelines recommend that infants with severe eczema, egg allergy, or both undergo skin prick testing in an allergist’s office. This practice eliminates the risk for an allergic reaction — and can allay parents’ fears.

Babies not meeting these criteria do not need peanut allergy testing, and other consensus guidelines do not recommend allergy testing before introducing potential allergens other than peanuts.

“It is a really personal and individualized decision about whether there should be any screening for the allergy before introduction, whether or not they should see an allergist, or whether or not they should just slowly and gradually introduce the food at home,” Baker said.

She suggested that in areas with poor access to specialty care, pediatricians could counsel parents to start with very small amounts, or they could administer the initial test dose of peanut butter, for example, in the pediatrician’s office.

What Can Pediatric Providers Do for Kids Who Already Have Allergies?

Once a child has a suspected food allergy, what next?

“If you have someone come to you for a likely food allergic reaction, certainly have them avoid the potential culprit food,” said Scott Sicherer, MD, professor of pediatrics and chief of the Division of Pediatric Allergy and Immunology at the Icahn School of Medicine at Mount Sinai. “Talk to them about treating allergic reactions, prescribe self-administrable epinephrine, and show them how to use it.”

But the next step really should be referral to a board-certified allergist, he said.

The allergist may recommend an approach that has become more common in the last 5 years — the use of food as oral immunotherapy (OIT), which involves administering increasing doses of allergen over time with the goal of inducing enough tolerance to prevent adverse events due to accidental exposure. Sicherer refers to this concept as “bite safety.” Studies on OIT have found that the strategy can lead to desensitization to peanuts, cow’s milk, and eggs by 60%-80%.

The first steps take place in an allergist’s office, where patients consume tiny amounts of the food protein in several small doses. If they tolerate that, they return the next day to repeat the highest dose from the previous day. If that goes well, they consume that amount like a medicine daily, returning every few weeks for a period of several months to gradually increase the dose to a maintenance dose that would allow them to safely consume a bite of the allergen, which for peanut protein is typically 300 mg or roughly one peanut.

Although simple in concept, Sicherer outlined several rules and restrictions for patients undergoing OIT. Pediatric providers can help support patient adherence to OIT by explaining and reinforcing these rules during child visits.

Safety is another issue. “You have to be a family where you’re very comfortable identifying an allergic reaction and treating it appropriately,” said Sicherer to describe what makes a patient a good candidate for OIT. Some patients are already comfortable avoiding the food and carrying epinephrine, and they might not reap much additional benefit from OIT.

The Latest New Thing

Omalizumab is an injectable monoclonal antibody that binds to free IgE, the antibody type that triggers allergic reactions. Initially approved for use for allergic asthma in 2003, a clinical trial published in 2024 led to its approval for food allergies.

Although omalizumab appears to be more effective than OIT in a head-to-head trial, the decision about which to try is not always straightforward, said Sayantani Sindher, MD, pediatric allergy and clinical immunologist at Stanford Medicine Children’s Health in Stanford, California, who helped conduct the pivotal trials of the drug.

A clear advantage of omalizumab is that it can address multiple allergens simultaneously, whereas OIT for more than one allergen can be cumbersome. Also, the protocol for starting omalizumab requires fewer office visits than OIT. The first three injections are given in the allergist’s office so patients can be monitored for adverse events and can learn how to do the injections themselves.

But the main drawback is that omalizumab requires an injection. “I have some kids who are needle-phobic,” Sindher said. “They’re willing to do whatever it takes to get away from doing the injection,” such as OIT.

How Pediatric Care Providers Can Support Families

Baker said clinicians should ask parents and caregivers about allergen avoidance and any reactions as the primary care provider may be the first point of contact when a child is experiencing a reaction. Mild reactions such as localized hives or itching may be treated with oral antihistamines.

Clinicians should also periodically review the signs of anaphylaxis with the family and ensure they feel comfortable administering epinephrine themselves. Baker recommended that pediatricians help families develop food allergy action plans using resources from the American Academy of Pediatrics or Food Allergy Research & Education.

Another critical issue for pediatric providers is monitoring nutritional status of patients with food allergies. “For example, if you have a child avoiding milk, you really should be keeping an eye on their vitamin D,” Baker said. Kids avoiding grain should be monitored for iron deficiency.

Lastly, food allergies can negatively affect quality of life, and Baker highlighted the need to consider psychosocial issues that may come up in kids with food allergies, such as bullying at school or eating disorders. Avoidant restrictive food intake disorder, an eating disorder motivated not by body image but by fear of reactions to food, is common in kids with food allergies. Pediatric providers are in a prime position to recognize such stressors and consider behavioral health referrals for these children.

Baker declared receiving research support from the NIH/NIAID and Pfizer. She reported serving on the Medical Advisory Board for the International FPIES Association. Sicherer reported receiving royalty payments from UpToDate and Johns Hopkins University Press; grants to his institution from the National Institute of Allergy and Infectious Diseases, Food Allergy Research and Education, Pfizer, and Regeneron; and personal fees from the American Academy of Allergy, Asthma and Immunology as Deputy Editor of the Journal of Allergy and Clinical Immunology: In Practice. Sindher reported having no financial conflicts of interest.

A former pediatrician and disease detective, Ann Thomas is a freelance science writer living in Portland, Oregon.