A large analysis of pediatric electronic health records provides real-world evidence that introducing peanut early in infancy is associated with falling rates of peanut and other IgE-mediated food allergies.
Study design
Researchers affiliated with the Children’s Hospital of Philadelphia and the American Academy of Pediatrics’ CER2 network reviewed records from 48 pediatric practices (31 within a mid-Atlantic academic system and 17 independent offices nationwide). They followed children from birth through age 3 who had at least one primary care visit before age 1. The team focused on IgE-mediated food allergy diagnoses and atopic dermatitis (eczema), a condition that marks higher allergy risk.
Three time periods were compared:
– Pre-guideline baseline (Sept 2012–Oct 2014), before recommendations to introduce peanut early.
– After initial guidance (Sept 2015–Aug 2017), which advised early introduction for high-risk infants (severe eczema or egg allergy).
– After the guideline addendum (Feb 2017–Jan 2019), which broadened recommendations and clarified testing and risk categories.
Cases were identified from diagnostic codes, allergy entries in the electronic health record, and prescriptions for epinephrine auto-injectors. Statistical models adjusted for age, sex, race, and ethnicity, and interrupted time series analysis tested whether trends shifted after guideline releases.
Key findings
– Peanut allergy rates declined after guideline implementation. In a two-year comparison window, peanut diagnoses dropped from 0.92% before guidelines to 0.67% after (a 27% decrease). In a one-year analysis that included the addendum period, rates fell from 0.79% to 0.45% (a 43% drop).
– Total IgE-mediated food allergy diagnoses also decreased. In the two-year analysis, overall food allergy fell from 1.98% to 1.23% (a 38% reduction). In the one-year comparison, rates declined from 1.46% to 0.93% (a 36% reduction).
– Adjusted analyses showed children born after the guideline periods had roughly a 35% lower hazard of peanut allergy and about a 31% lower hazard for any food allergy compared with those born before the recommendations.
– The reduction in peanut allergy occurred in children both with and without eczema, indicating benefit beyond the initially targeted high-risk group. In one subgroup analysis, infants with existing egg allergy were less likely to develop peanut allergy after the guidelines; children with eczema did not show a significant change in that particular subgroup analysis.
– The relative frequency of allergens shifted: before the guidelines, peanut was the most commonly diagnosed food allergy, followed by egg and cow’s milk. After the guidelines, egg became the most common, peanut moved to second place, and cow’s milk diagnoses also declined.
– Interrupted time series models showed a clear downward trend in food allergy diagnoses following guideline release; the decline specifically for peanut was present but less pronounced in that model.
– The characteristics of diagnosed children changed modestly over time: more very young infants (under four months) appeared among those diagnosed after the guidelines, and a smaller proportion of diagnosed children were Black, Asian or Pacific Islander, or Hispanic in the post-guideline periods.
Interpretation and practical guidance
The investigators conclude that early peanut introduction appears increasingly adopted in primary care and may be contributing to lower rates of IgE-mediated food allergies at the population level. Independent pediatric allergy clinicians interviewed by the study authors reinforced current practice points:
– Introduce peanut-containing foods once the infant is developmentally ready for solids, typically around 6 months but not before 4 months. For infants at high risk (severe eczema or existing egg allergy), consider starting peanut as early as 4–6 months in an age-appropriate, safe form and ideally after discussing with a healthcare provider.
– After first introduction, continue regular ingestion (for example, a few times per week) to help maintain tolerance.
– Use non-choking forms such as thinned smooth peanut butter mixed into purees or infant-safe peanut puffs; do not give whole peanuts or thick globs that pose a choking hazard.
– Other allergens such as cooked egg and cow’s milk can also be introduced around 4–6 months for most infants. For the majority, this can be done at home without prior allergy testing, although clinicians can help identify the small minority of babies who truly are high risk and may benefit from specialist input.
Bottom line
This large, multicenter electronic health record study supports guideline recommendations that early introduction of peanut — and timely introduction of other allergenic foods — is associated with reduced rates of IgE-mediated food allergy diagnoses in early childhood. Clinicians and caregivers should continue to follow current guidance on age-appropriate, safe introduction of allergenic foods, with early consultation for infants judged to be at high risk.