Introduction of peanut in sensitized infants with reported prior reactions

Published online September 1, 2024

Current diagnostic guidelines often recommend classifying a patient food allergic when a likely history of reactions is obtained and specific IgE antibodies (sIgE) are demonstrated to the culprit food. A correct diagnosis is crucial at a young age, when trying to prevent peanut allergies by early introduction of peanut.

In a prospective cohort study, published in The Journal of Allergy and Clinical Immunology: In Practice by Verhoeven et al., 186 infants aged 4-12 months with reported immediate reactions to peanut at home after early introduction were investigated. The presence of sIgE to peanut was determined using skin prick tests (SPT). In 163 infants with Sampson severity grade I to III reactions at home, peanut open food challenges (OFC) were performed to confirm the diagnosis.

In 69% of the infants, sIgE to peanut was detected. However, in 120 out of 163 infants, peanut challenges had negative results. In infants with clear sensitization to peanut (>4 mm SPT wheal) and a history of immediate reactions to peanut at home, 56% of the challenge outcomes were negative. All infants with negative peanut OFCs were advised to introduce peanut into their diet and eat a minimum of 10 grams of peanut butter at least once a week. The development of long-term tolerance to peanut was shown at 6 months and 2 years after the OFC in >95% of the infants. One patient that introduced peanut after a negative OFC was considered peanut allergic.

The authors conclude that the study demonstrates that food challenges should be considered in young infants to correctly diagnose peanut allergy. This allows successful secondary prevention in those that have already developed sIgE against peanut but do not have generalized reactions to peanut yet.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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