Cow’s milk oral immunotherapy in real-life: up to 15-year follow-up study

Background.Oral immunotherapy (OIT) is a promising strategy for severe and persistent cow's milk (CM) allergy.However, clinical experience concerning long-term follow-up is scarce.The objective is to assess long-term efficacy and safety of maintenance phase of OIT in real-life. Methods.Prospective study of children with severe IgE-mediated CM allergy that underwent CM-OIT, and were followed-up by the authors, up to 15 years.Complete desensitisation was defined when maintenance dose of 200 mL daily was achieved.Characterization (clinical and laboratory) was performed before and after OIT during follow-up.Results.Thirty-three patients enrolled: 58% male, 70% asthmatics and 67% with previous history of CM-anaphylaxis.Mean age at onset of CM-OIT was 7±2.8 years.Complete desensitisation was ensured in 94% (free diet with dairy 200mL of CM or equivalent).During maintenance phase 79% developed allergic reactions, with anaphylaxis in 33%, including exercise-induced anaphylaxis in 15% and with cheese intake in 15%.We stress that eosinophilic esophagitis appeared in 12%.Specific IgE levels and skin prick tests (SPT) to CM and casein have significantly decreased, and in most patients (61%) SPT became negative.When available, specific IgG4 levels have significantly increased.Conclusions.This real-life study supports long-term efficacy and safety of CM-OIT.CM-OIT had a high success rate, allowing diet without restrictions with persistence of the effect up to 15 years.However, one-third of patients experienced anaphylaxis during maintenance phase.CM-OIT should always be performed by allergy experts and only motivated families should be enrolled, since long-term follow-up is required, and daily intake of CM is needed to ensure desensitization. Key wordsCow's milk allergy; desensitization; food allergy; Long-term follow-up; oral immunotherapy. Impact StatementReal-life study that supports efficacy and safety of cow's-milk-oral-immunotherapy in long-term follow-up, with high success rate of complete desensitization, although one-third had anaphylaxis during maintenance-phase and some had eosinophilic esophagitis.