Supplementary Material for: Egg ladder versus oral immunotherapy in infants with egg allergy: A single-center, retrospective cohort study

Introduction: Egg allergy restricts dietary diversity. Although oral immunotherapy (OIT) has demonstrated efficacy in treating egg allergy, this approach carries the risk of anaphylaxis. In the egg ladder (EL) approach, egg proteins are gradually introduced from extensively heated forms to less processed ones. Here, we aimed to compare the efficacy and safety of EL versus OIT in infants with egg allergy.
Methods: This single-center retrospective cohort study involved children aged <2 years who had been diagnosed with IgE-mediated egg allergy between 2014 and 2022. We utilized a historical cohort design comparing patients treated with OIT (2014–2018) with those treated with the EL approach (2018–2022). The study’s primary outcomes were: (1) tolerance to whole egg (at least half of one whole egg) and (2) tolerance to egg-containing processed foods (ECPFs). Adverse events (AEs) were also assessed.
Results: A total of 163 children received OIT, whereas 89 underwent EL. Whole‑egg tolerance after 2 years of follow-up was similar between the groups (EL: 58% vs. OIT: 52%, P = 0.355). ECPF tolerance was higher with EL than with OIT (EL: 80% vs. OIT: 64%, P = 0.014). The overall AE rates were comparable between the approaches (EL: 28% vs. OIT: 34%, P = 0.397); however, treatment‑related anaphylaxis occurred only with OIT (three cases). Kaplan–Meier curves showed no difference in whole‑egg tolerance between the two approaches (P = 0.681), but the time to ECPF tolerance was shorter with EL (P = 0.009).
Conclusion: In this real-world cohort of infants with egg allergy, the EL approach achieved whole‑egg tolerance comparable to OIT and a substantially faster and higher tolerance to egg-containing processed foods, as expected given the EL protocol design. Although overall AE rates were similar between the approaches, no treatment‑related anaphylaxis occurred with EL, suggesting that the EL approach represents a safer and more practical strategy for dietary expansion in this age group.