Title: Efficacy and safety of oral immunotherapy for Peanut Allergy A Grade assessed systematic review and meta analysis of randomised controlled trials.

Introduction: Peanut allergy is a common and potentially life-threatening condition affecting up to 2% of children in Western countries. Management traditionally relied on avoidance, but in 2020, the FDA approved peanut oral immunotherapy (pOIT) to induce desensitization. This meta-analysis evaluates the efficacy and safety of pOIT versus placebo by incorporating newly published trials to inform clinical decision-making.

Methods: This systematic review and meta-analysis followed PRISMA guidelines and Cochrane methodology, with registration number . Randomized controlled trials comparing peanut oral immunotherapy (pOIT) to placebo in IgE-mediated peanut allergy were included. Primary outcomes were gastrointestinal disorders and wheezing. Data were pooled using a random-effects model in RevMan 5.4.1, and evidence certainty was assessed using the GRADE approach.

Results: This meta-analysis included 15 RCTs with 1530 patients (1014 pOIT, 516 placebo). pOIT significantly increased gastrointestinal disorders (RR = 1.90; 95% CI: 1.25-2.89; p = 0.003) and epinephrine use (RR = 2.29; 95% CI: 1.43-3.67; p = 0.0006). No significant differences were observed in wheezing, eczema, respiratory disorders, respiratory symptoms, or vomiting. Heterogeneity ranged from low to high across outcomes. Certainty of evidence was rated high for gastrointestinal disorders, epinephrine use, and respiratory symptoms; moderate for wheezing, eczema, and vomiting. Heterogeneity was primarily driven by specific outlier studies, as identified through sensitivity analyses.

Conclusion: Peanut oral immunotherapy (pOIT) increases desensitization in patients with peanut allergy but is associated with a significantly higher risk of gastrointestinal side effects and epinephrine use, reflecting an increased rate of systemic allergic reactions. While outcomes such as wheezing, eczema, and respiratory symptoms showed no significant differences, variability in study design and adverse event reporting limits broad generalizability. These findings emphasize the need for careful patient selection, pre-treatment counseling, and close monitoring. Future research should focus on protocol standardization, long-term outcomes, and strategies to minimize adverse effects while maintaining efficacy.