Allergic rhinitis (AR) is in inflammatory disease characterized by nasal symptoms. It affects 20-25% of Canadians and is recognized as the most common allergic disorder worldwide. Patients can experience one of several types of responses to allergen onset hence a key hurdle to developing effective treatment plans is accurate diagnosis. The allergic responses are characterized by an early response, with a subsequent late response in a subgroup of patients. Based on severity of nasal symptoms, patients can be stratified as early responders, protracted early responders or dual responders. Presently there is limited knowledge of the mechanisms underscoring the observed heterogeneity in allergic responses. This project will address this limitation by aiming to differentiate the types of AR using molecular differences in blood. This work will help lead to the development of diagnostic tools hence improving diagnosis and management of AR, furthering the mandates of our partner organization ? PROOF Centre for Excellence.