Intranasal Diagnostics in Food Allergy: a Feasibility Study

Inclusion Criteria: * Aged 6 - 17 years old * Physician-diagnosis of food allergy on the basis of: * Positive oral food challenge to the causative food (conducted under medical supervision) within the last 12 months; OR * History of convincing clinical reaction to the causative food within the last 12 months AND positive skin prick test within last 12 months; OR * Evidence of \>95% likelihood of food allergy (on the basis of serum specific IgE or skin prick test (SPT) 8mm or above to the causative food allergen within past 12 months * Written informed consent from parent/guardian, with assent from children aged 8 years and above wherever possible. Participants aged over 16 years will need to provide their owned informed consent. Exclusion Criteria: * Contraindicated as acutely unwell or current unstable asthma: * Acute wheeze in last 72 hours requiring treatment * Febrile ≥38.0oC in last 72 hours * Recent admission to hospital in last 2 weeks for acute asthma * Current medication * Use of asthma reliever medication in last 72 hours * Recent administration of a medication containing antihistamine within the last 4 days * Current oral steroid for asthma exacerbation or course completed within last 2 weeks