Safety of a novel oral immunotherapy approach in preschool children with single and multiple food allergies

Background: Oral immunotherapy (OIT) has emerged as a promising food allergy treatment with significant evidence of increased efficacy in preschool-aged children. However, current OIT protocols are generally burdensome and focus on single food allergies, while many children have multiple food allergies. A feasibility-oriented approach that minimizes the impact of therapy while allowing both single and multiple food allergy treatment is important to enhance accessibility for routine clinical practice. This study assesses the safety of a feasibility-oriented OIT protocol in preschool-aged children with single and multiple food allergies. Methods: This single-center prospective intervention study included children aged 9–24 months with proven food allergy (sensitization and a positive oral food challenge (OFC)). After a short dose escalation phase, children received one year of low-dose (300 mg protein/day) OIT, followed by an exit OFC four weeks after stopping therapy. Children with multiple food allergies received OIT for up to four allergens. Each allergen treatment is referred to as an OIT trajectory. Allergic dosing reactions (ADR) were recorded and classified using Sampson's severity score (grades I-V). Results: Between May 2019 and Oct 2022, 124 children (median age 17 months, IQR 11–20 months) started OIT for 189 food allergies. Peanut (n = 52), cashew nut (n = 46) and egg (n = 38) allergies were the most common. The median number of hospital-based dose escalations per patient was three (IQR 2–5). ADR occurred in 89 children and 117 OIT trajectories, most frequently during dose escalation (48.1%). Most reactions (95.3%) were mild (Sampson I-II) and resolved spontaneously (55.6%) or with antihistamines (29.9%). Ten reactions were severe (Sampson III-IV), of which one required epinephrine. Ten trajectories were discontinued due to side effects. Conclusions: Our novel feasibility-oriented OIT protocol appears safe for various allergens and multifood OIT in preschool-aged children. Side effects were common but typically mild. However, they may lead to therapy discontinuation. Clinical Trial Registration: https://www.onderzoekmetmensen.nl/en/trial/49735, identifier NL7663.