Life-threatening anaphylaxis in children with cow's milk allergy during oral immunotherapy and after treatment failure

Background: Oral immunotherapy (OIT) is a promising therapeutic approach for children with persistent IgE-mediated cows milk allergy (CMA) but data are still limited.Objective: To analyze the prevalence of life-threatening anaphylaxis in children with persistent CMA undergoing OIT and to evaluate potential risk factors.Methods: This is a retrospective cohort study among children with persistent CMA undergoing OIT over a 20-year period, following a specific Oral Tolerance Induction protocol. Adverse reactions during the whole period and data on long-term outcome were registered. Descriptive and nondescriptive statistics were used to describe data.Results: Three hundred forty-two children were evaluated. During OIT, 12 children (3.5%) presented severe anaphylactic reactions that needed an adrenaline injection. None required intubation, intensive care unit (ICU) admission, or showed a fatal outcome. Five of them abandoned OIT, five reached unrestricted diet and the others are still undergoing OIT. As far as outcome is concerned, 51.2% reached an unrestricted diet; 13.5% are at the build-up stage; and 28.0% (97 patients) stopped the OIT. Among these 96 children, 6.3% experienced a severe reaction induced by accidental ingestion of milk with two fatal outcomes.Conclusions: The risk of life-threatening reactions was nearly two times lower (3.5% vs. 6.3%) among patients assuming milk during OIT than in those who stopped the protocol. A trend in favor of more severe reactions, requiring ICU admission, or fatal, was shown in patients who stopped OIT.