Beyond first sip: combination of intermittent cow’s milk exposure and atopic dermatitis associated with severe IgE mediated cow’s milk reactions—a retrospective study

The prevalence of IgE-mediated cow’s milk allergy in Canada has been increasing and is recognized as the leading cause of fatal anaphylaxis in school aged children. Experts are unable to predict which individuals will have spontaneous resolution of cow’s milk allergy and who will have a persistent phenotype, therefore primary prevention is key. The aim of this study was to identify risk factors leading to the development of an IgE mediated cow’s milk allergy. A 54-item survey was provided to parents of children aged 0–4 years with an allergist diagnosed IgE mediated cow’s milk allergy. Out of the 24 participants who completed the survey, 21 were used in the analysis. All infants were term and 57% of participants reported intermittent exposure to cow’s milk formula. Of the infants with intermittent cow’s milk exposure, majority (75%) experienced the exposure prior to hospital discharge. Infants with both atopic dermatitis and intermittent exposure to cow’s milk formula had more severe reactions. This is the first study to our knowledge that found an association between reaction severity and having multiple risk factors- atopic dermatitis and intermittent exposure to cow’s milk formula. Majority of the intermittent cow’s milk exposure occurs prior to discharge from hospital. Further research in the area is required, however policy changes to mitigate associated risk could include use of donor breast milk or extensively hydrolyzed formula for supplementation, or recommendations to continue regular cow’s milk formula following introduction.