High Risk Infants who are Low Dose Tolerant after Peanut Oral Food Challenges

Background Early peanut (PN) introduction may prevent peanut allergy in at-risk children. Little data exists regarding early introduction for infants with large skin prick tests (SPT) or high peanut IgE levels, who are not often offered oral food challenges (OFC). Objective To retrospectively assess tolerance of a low dose (1 gram) of peanut in infants at risk for peanut allergy, including highest-risk infants (HRI) with SPT wheal >7mm. Methods We reviewed PN OFCs performed over a two-year period at our pediatric allergy center. Low-dose PN OFC was offered to all infants considered at risk for PN allergy, regardless of peanut SPT or IgE results. Dosing was escalated after OFC at home. Results Of infants with SPT wheal 4 mm (n=40), 25 (63%) were low-dose-tolerant, and Ara h2 IgE was significantly lower compared to non-tolerant individuals (median 0.62 versus 6.49 kU/L, p7mm (n=22), 12 (55%) were tolerant, with median SPT 9mm (range 8-11mm), PN-IgE 1.1 kU/L (0.3-10.7 kU/L) and Ara h2 1.6 kU/L (0-9.57 kU/L). Age, sex, race, eczema, and egg sensitization did not affect tolerance regardless of SPT size. After 3-6 months, most infants tolerant at OFC were gradually able to consume larger doses of PN. Conclusion Many infants with PN-SPT >4mm are tolerant of low-dose peanut, and Ara h 2 IgE may be predictive for clinical tolerance among these infants. Low-dose PN-OFC with gradual updosing may help prevent PN allergy in a greater number of at-risk infants.