Background: Cow's milk allergy (CMA), one of the main types of childhood allergy, considerably impairs patient quality of life. Allergen avoidance is difficult, and mistakes are common. Therefore, new treatment strategies such as oral immunotherapy (OIT) have been sought for patients with CMA. Our objective was to review current evidence on immunological changes, efficacy, and safety when using OIT as an alternative to an avoidance diet in the treatment of children with IgE-mediated CMA.

Methods: We performed a systematic review and subsequent meta-analysis of all randomized controlled studies published to date in which OIT is used to treat CMA in children. We evaluated immunological effects, acquisition of desensitization, and adverse events. Immunological changes were examined by means of a meta-analysis of individual patient data.

Results: Desensitization using OIT to cow's milk is 10.2 times more likely than in non–OIT-treated patients. The decrease in cow's milk–specific IgE levels was found to differ by 8.1 kU_A/L between OIT-treated patients and those on an avoidance diet. This difference was not statistically significant (P=.318). Although side effects are common, they usually involve mild reactions that are easy to manage without parenteral epinephrine.

Conclusion: OIT can be considered safe and effective (in terms of acquiring desensitization) and reasonably safe (mild-to-moderate adverse events, little need for parenteral epinephrine) in patients with CMA. Although OIT leads to changes in cow’s milk–specific IgE levels, the differences between OIT-treated and non–OIT-treated patients are not significant. More studies are needed to evaluate other immunological changes that may occur, such as the increase in IgG4 levels.

Key words: Avoidance diet. Children. Cow's milk allergy. Food allergy. Meta-analysis. Oral desensitization. Oral immunotherapy. Systematic review.