Peanut Oral Immunotherapy in Children: An Italian Single-Center Retrospective Cohort Study

Introduction: Peanut oral immunotherapy (P-OIT) is an emerging treatment strategy for peanut allergy (PA). Although a standardized pharmaceutical product, Peanut (Arachis hypogaea) Allergen Powder-dnfp, has been approved in several countries, it is not universally available. In such contexts, real-world protocols using readily utilizable peanut products may represent an alternative approach. This study aimed to describe the feasibility, safety, and clinical outcomes of P-OIT using toasted peanuts in a real-world effort in a pediatric population. Methods: This single-center retrospective cohort study enrolled children who initiated P-OIT at our tertiary pediatric hospital Allergy Unit between April 2015 and December 2024. Demographic and clinical features, allergy test results, and information about P-OIT were recorded. Desensitization was defined as tolerance of 630 mg of peanut protein (PP). Results: Sixty patients (51.7% male; median age 8.2 years) were included. 22/60 (36.7%) achieved desensitization within a median time of 22.7 months. 21/60 (35%) were still undergoing P-OIT at a median tolerated dose of 100 mg of PP, and 17/60 (28.3%) discontinued treatment, most commonly due to loss to follow-up (44%). At least one adverse reaction occurred in 43/60 (71.7%) patients, predominantly mild and self-limiting (68.3% resolved spontaneously, 39.5% occurred at home). However, 11/60 (18.3%) showed anaphylaxis, and 3/60 (5%) received adrenaline. A reduction in Ara h 2 serum-specific IgE levels compared to the baseline was observed in patients completing escalation (p = 0.03). Conclusions: In this real-world single-center cohort, P-OIT using toasted peanuts was feasible in a subset of patients and was associated predominantly with mild adverse reactions, although systemic reactions were also recorded. Treatment discontinuation and adherence remain relevant challenges. These findings highlight the need for prospective, controlled studies to better define the role, safety profile, and patient selection criteria for food-based P-OIT protocols in settings where standardized products are not available.