Dynamic Changes of Nasal Airflow Resistance During Provocation with Birch Pollen Allergen

Abstract

Over 500 million people suffer from allergic rhinitis around the world. This huge problem causes, in addition to individual impacts, a substantial economic burden to societies. There is a lack of an objective measurement method producing a reliable, accurate and continuous measurement data about the dynamic changes in nasal function. Here, a method to assess the nasal airflow resistance as a continuous signal is proposed and used to compute resistance values during the birch pollen provocation test. The required pressure recording is measured using a nasopharyngeal catheter and the flow recording is measured using respiratory effort belts calibrated with the new method. Ten birch pollen allergic and eleven non-allergic volunteers were challenged with control solution and allergen solution. Continuous nasal airflow resistance signals were computed and analyzed for the dynamic changes in the nasal airflow resistance. The derived signals show in great detail the intensity and timing differences in subjects’ reactions. Quantitative results of resistance changes indicate that allergic and non-allergic subjects can be differentiated in a statistically significant degree using the proposed method. The method opens entirely new possibilities to research accurately the dynamic changes in non-stationary nasal function and could increase the reliability and accuracy of diagnostics and assessment of the effect of nasal treatments.