Peanut allergy prognosis up to age 12: Oral food challenge‐based study in Japanese children

Background The natural history of peanut allergy based on oral food challenge (OFC) outcomes has been rarely reported. We investigated the clinical course of peanut allergy up to 12 years of age using OFC results. Methods The participants were children diagnosed with peanut allergy by 3 years of age, defined by peanut sensitization with definitive immediate‐type symptoms or a positive OFC. Stepwise OFCs were performed on separate days with total ingestion amounts of 0.5, 3, and 10 g of peanut. Tolerance was assessed through regular OFCs and defined as a negative result on a 10‐g OFC or the ability to consume ≥10 g of peanut. We retrospectively analyzed OFC outcomes up to 12 years of age. Results We included 42 children (81% male) with a median peanut‐specific IgE (sIgE) of 16.8 kU A /L at age 3; 16 children (38%) had a history of anaphylaxis. Overall, 82 OFCs were performed; four children (10%) discontinued follow‐up. Kaplan–Meier–estimated tolerance acquisition rates were 2%, 18%, and 36% at 4, 6, and 12 years of age, respectively. Compared with the non‐tolerant group, the tolerant group had lower peanut‐sIgE at 3 years of age (median: 3.67 vs. 27.6 kU A /L; adjusted HR for log‐transformed value: 0.31, 95% CI: 0.10–0.96, p = .041), and lower peanut‐sIgE at 6 years and Ara h 2‐sIgE at 6 and 9 years of age. Conclusions One‐third of Japanese children diagnosed with peanut allergy by 3 years of age achieved tolerance by 12 years of age. Lower peanut‐sIgE levels at 3 years of age were associated with subsequent tolerance acquisition.