150 International Survey on the Management of Allergic Rhinitis by Physicians and Patients (ISMAR). Physicians' View

Cologne, Germany; Praxisgemeinschaft im Kapuzinerkarree, Aachen, Germany; Institute of Aerodynamics, RWTH Aachen, Aachen, Germany. Background: Our investigation aimed to visualize the 3-D spatial distribution of nasal cavity mucosal swelling under levocetirizine prophylactic treatment on exposure to allergens. This study made use of standard rhinologic diagnostics such as rhinomanometry and acoustic rhinometry, as well as 24 hours rhinometry and magnetic resonance imaging (MRI). Methods: A suitable test subject with a history of allergic rhinitis was identified during the symptom-free interval after the pollen season when she showed signs of “minimal persistent inflammation,” consisting of pronounced reaction to nasal challenge with allergens. Provocation with birch pollen caused moderate symptoms of allergic rhinitis. Nasal provocation tests were performed before and after 2 and 5 weeks of treatment with levocetirizine 5 mg OD. Long-term rhinometry was carried out to detect the progress of the nasal cycle and relative flow variances over 24 hours. Flexible air tubes required for this new procedure made it possible to quantify relative pressure changes. High resolution MRI was also used to capture, visualize, and process the geometrical data of the nasal cavity immediately before and after the challenge tests. Based upon the MRI data, we computed the nasal airflow using a computational fluid dynamics (CFD) nasal model to visualize intranasal pressure and flow. Rhinomanometry and acoustic rhinometry were performed to validate the results. Results: After 36 days of treatment with levocetirizine, a 16% improvement in the nasal flow relative to baseline and an increase by 3.4 cm3 of the total nasal baseline volume were documented as compared to the allergen challenge of the untreated case. 3-D images illustrated that treatment inhibited the allergen provocation effects on nasal airflow and normalised nasal flow velocity and pressure, including in the olfactory region. Conclusions: Besides improving the nasal airflow to an almost normal pattern, levocetirizine also helps prevents the patient from having an allergic response, even 24 hours after last drug intake. Furthermore, it can improve olfaction by restoring airflow to the olfactory region.