A single-institution US study in the Journal of Allergy and Clinical Immunology: Global has reported a steady rise in emergency department (ED) visits for food-induced allergic reactions (FIR) in infants — likely reflecting current guidelines on earlier food allergen introduction. Infants had more than twice the odds of experiencing FIR in the post-guideline era.

As adoption of the new recommendations expands, families and caretakers need guidance in the event of food reactions, according to researchers from the Division of Pediatric Allergy/Immunology and Rheumatology at UCLA School of Medicine. While the early-introduction recommendations decrease the risk for food allergies later in life, the authors of the brief report, led by Aaron T. Chin, MD, stressed that a proportion of children will be already sensitized and clinically reactive at the time of the first feed.

“Based on our clinical experience, we suspected that rates of [ED] visits for infants would be increasing,” co-author Maria I. Garcia Lloret, MD, told Medscape Medical News. “As allergists, we receive regular referrals for infants experiencing food reactions, many times with an associated [ED] visit, and our study’s findings were in line with our experience in the clinic.”

Study Details

Though national guidelines now recommend early introduction of allergenic foods to young children, whether these have affected ED encounters was poorly understood. To fill that knowledge gap, the study compared pediatric ED encounters at UCLA for FIR, including food-induced anaphylaxis (FIA), during the pre- and post-guideline periods, 2013-2016 and 2022-2024.

The retrospective analysis of 67,059 ED visits identified 350 visits for FIR and 182 for FIA in patients age-stratified into two groups: infants 0-1 year and children 2-5 years. Overall, both FIR and FIA annual rates increased significantly over time. In infants the odds ratios (OR) of increase were 1.15 (P = .005) and 1.27 (P = .002), respectively. In multivariate analysis, post-guideline infants had an OR of 2.21 (95% CI, 1.37-3.55).

No significant change was observed in the 2- to 5-year group. Older children were more likely to have been evaluated by an allergist and prescribed epinephrine, with their caregivers educated on recognizing and managing allergic reactions, Garcia Lloret said. “These may constitute protective factors likely to avert [ED] visits.”

Compared with the pre-guideline period, annual FIR visit rates among infants aged 0-1 year rose significantly: OR, 1.111 per year (95% CI, 1.056-1.169; P < .001). FIR rates remained stable in children aged 2-5 years (OR, 1.019 per year; 95% CI, 0.974-1.065; P = .419).

For the more serious FIA, rates in infants rose from 8.5 to 38.9 per 10,000, for a 358% increase. In terms of refractory anaphylaxis, rates did not change significantly in either infants or older children.

The study also examined covariates affecting FIR, including preexisting eczema, sex, race, under-represented minority status, prior allergy visits, and prior epinephrine prescription. In study infants, FIR predicted preexisting eczema (OR, 3.78; 95% CI, 2.35-6.07).

In the older age group, FIR was associated with male sex (OR, 1.54, 95% CI, 1.01-2.34), eczema (OR, 1.87; CI, 1.19-2.95), prior allergy visits (OR, 4.48; 95% CI, 2.64-7.61), and preexisting epinephrine prescription (OR, 2.56; 95% CI, 1.40-4.69). “Our study was not able, however, to correlate the severity of eczema with the likelihood of reaction,” Garcia Lloret said.

Her center has now implemented an educational tool to guide families on the early introduction of allergenic foods, including the recognition and management of food reactions. “These have been distributed to our primary care offices and shared with families during infant well-child checks,” she said.

Commenting on the study but not involved in it, Ruchi S. Gupta, MD, MPH, director of the Institute for Public Health and Medicine - Center for Food Allergy & Asthma and a professor of pediatrics at Feinberg School of Medicine, Northwestern University, Chicago, said the findings make sense. “If families are introducing allergens earlier, then more reactions are also occurring in the first year of life, with more [ED] visits,” she said.

“Normally these reactions would have happened later when the child tried the food. We need to better identify the infants who are already allergic by understanding the true risk factors in addition to eczema,” she added.

Is it possible that early-introduction guidelines have been implemented too hastily? No, said Gupta. “The data from the 2015 LEAP study showed an 80% decrease in food allergy incidence in high-risk infants who started eating peanuts early. These data were so strong that we made recommendations for all infants.”

Added Garcia-Lloret, “Aside from children with severe eczema and/or known food allergy, for whom we recommend allergist consultation, common allergens can be introduced to infants early. However, parents should receive the proper guidance on what to expect.”

In otherwise normal infants, exposure to a food to which they are already sensitized will result in a mild urticarial rash that can be managed with antihistamines and at-home monitoring. “However, more severe reactions involving the respiratory or gastrointestinal systems can occur. This raises the concern for anaphylaxis and parents should also be educated on proper emergency care such as calling 911,” she said.

Gupta added that the development of an eight-food introduction study is currently underway to learn more about factors influencing early sensitization and allergy. “These factors include the microbiome, genetics, eczema, and the environment.”

More families are introducing egg and peanut early, but once you introduce a food you must keep it in the diet, two to three times a week ideally, Gupta said. “Also, use a barrier cream around the mouth when introducing so there’s no contact dermatitis, which can be mistaken for an allergic reaction.” Finally, introduce foods you eat in your family diet.

As to unanswered questions, Gupta asked “Does increased diversity in the first year of life of other common allergens prevent those allergies as well? If we protect the skin barrier early can we prevent the atopic march?”

Future studies should evaluate guideline adoption, parental guidance, and the long-term impact of early allergen introduction and whether guidance for high-risk infants reduces ED utilization, the authors wrote. Fortunately, despite these overall rising visit rates, those for food-induced refractory anaphylactic reactions remained stable.

This study was funded by the National Institutes of Health/National Center for Advancing Translational Science UCLA. The authors declared no conflicts of interest. Gupta reported receiving funds from Food Allergy Research and Education.