Safety and clinical predictors of reacting to extensively-heated cow's milk challenge in cow's milk-allergic children: A prospective cohort study

Abstract

Background: Many children with IgE-mediated allergy to cow's milk (CM) can tolerate CM in baked foods. The clinical characteristics and severity of reactions of children who react to baked CM at open food challenge (OFC) are not well defined. Method(s): Children presenting to our tertiary referral clinic with a diagnosis of CM allergy and excluding all CM in their diet were offered OFC to baked CM. Challenges were performed with incremental dosages to a total of one baked muffin containing 0.5 g CM protein following a standardised protocol. Data was collected prospectively from 2010-2013. Result(s): OFC to baked CM were carried out in 70 children, of whom 51 (73%) passed and successfully incorporated baked CM into their diet. 19 children (27%) reacted to their challenge, of whom 4 (21%) experienced anaphylaxis (according to WAO criteria) and required intramuscular adrenaline. Significant predictors of clinical reactivity to baked CM were: asthma; asthma requiring preventer therapy; IgE mediated clinical reactions to more than 3 food groups; and those with a past history of CM anaphylaxis. Skin prick testing to CM or prick-to-prick testing to a slurry of the challenge muffin was not predictive of challenge outcome. Summary:We believe these data provide valuable additional information about risk stratification for children where a baked CM challenge is being considered. Based upon our population, we recommend that initial introduction of baked CM in CM allergic children should occur under direct medical supervision in an environment where severe reactions can be managed appropriately. Particular caution should be exercised in those CM-allergic children who have a combination of asthma, multiple food allergies and past history of anaphylaxis to both CM and other foods.