Unexpected Cow’s Milk Proteins in a “Vegan” Easter Egg as a Cause of Anaphylaxis

Background: Cow’s milk is the most frequent cause of food allergies in children, with caseins and β-lactoglobulin being considered the main allergens. Concerningly, numerous international agencies have highlighted a growing risk of allergic reactions in milk-allergic individuals after the consumption of products labelled as “vegan”. Objectives: We describe the case of a 3.5-year-old boy with a history of a food allergy to milk who complained of anaphylactic clinical symptoms after eating a vegan Easter egg. The aim of this study was to confirm the cause of the clinical symptoms, searching for the possible presence of milk proteins in the vegan chocolate. Methods: An experimental approach based on electrophoretic (SDS-PAGE) and immunoenzymatic techniques (ELISA) was applied. Results: SDS-PAGE indicated the presence of milk proteins, which was confirmed and quantified via ELISA (3034 ± 115 mg/kg). Conclusions: The data obtained demonstrate that the severe clinical symptoms were due to the unexpected presence of milk proteins in a vegan product, underlining the critical need for rigorous allergen quality control throughout the food industry.