Skin prick testing with extensively heated milk or egg products helps predict the outcome of an oral food challenge: a retrospective analysis

Charts from a single allergy clinic were reviewed for any patient with a negative SPT to EH milk or egg, prepared in the form of a muffin. Data collected included age, sex, symptoms of food allergy, co-morbidities and the success of the OFC to the muffin.Fifty-eight patients had negative SPTs to the EH milk or egg in a muffin and underwent OFC to the appropriate EH food in the outpatient clinic. Fifty-five of these patients tolerated the OFC. The negative predictive value for the SPT with the EH food product was 94.8%.SPT with EH milk or egg products was predictive of a successful OFC to the same food. Larger prospective studies are required to substantiate these findings.Although estimates of prevalence are heterogeneous in medical literature, cow’s milk and hen’s egg are consistently reported as two of the most common food allergens in the pediatric population [1]. The diagnostic investigation for food allergy commences with skin prick testing (SPT) with commercial extracts of suspected allergens. In cases of true IgE-mediated allergic reactions, a localized cutaneous swelling in the form of a ‘wheal’ usually ensues. Typically, negative SPTs are followed by an oral food challenge (OFC), the gold standard, to definitively rule out food allergy.The standard management of food allergy is strict avoidance of the confirmed allergen [2]. For both milk-allergic and egg-allergic patients, this restriction limits dietary options. Undoubtedly, adherence to this regimen can be burdensome, limits dietary variety and negatively impacts quality of life.In recent years, evidence has emerged suggesting that the majority of children with milk and/or egg allergy can tolerate these foods when they are extensively heated (EH) [3,4]. Extensive heating alters the allergenic proteins to which IgE antibodies typically form and allergenicity is attenuated in cases of certain allergens such as milk and egg [5]. Furthermore, it has been suggested that exposure may be therapeutic and extende