Children aged 6 months to 15 years requiring an oral food challenge to one of the study foods (milk, egg, peanut, sesame or cashew nut) will be invited to participate in the study.~Eleven centres across the UK will be recruiting participants and perforning clinical procedures, such as skin prick testing and oral food challenges (OFC), as per standard clinical care.~Participants will be randomised 4:5 to either have the standard-of-care, i.e. oral food challenge to the suspected food, or take BAT (MAT if BAT inconclusive) into account to decide whether or not OFC will be required: if BAT/MAT is positive, food allergy will be confirmed without doing OFC; if BAT/MAT is negative, participants in the biomarker arm will undergo OFC.~The primary outcome is the proportion of positive OFC in the biomarker arm compared with the standard-of-care arm.~Secondary outcomes are: number of OFC, quality of life, anxiety and costs associated with the diagnostic work-up.
The BAT Impact study is a prospective multicentre study in the UK using a biomarker-led study design to compare the incidence of adverse events (defined as allergic reactions during oral food challenges) in a randomized-controlled trial. Patients will either follow the standard-of-care (i.e. an oral food challenge in case of equivocal SPT/sIgE) or follow a basophil activation test (BAT)/mast cell activation test (MAT)-based strategy, i.e. patients with a positive BAT or MAT are dispensed of an oral food challenge (OFC) and patients with a negative BAT/MAT undergo an OFC.