Perceptual and physiologic effects of histamine challenge on nasal breathing

The purpose of this study is to determine the effect of histamine-induced n asal congestion on nasal airflow and the perception of externally applied r esistance to nasal breathing. Nasal cross-sectional area and nasal airflow during free breathing were measured in 15 adult subjects before and after h istamine challenge. The threshold for perception resistance to nasal breath ing was determined using a dynamic perturbator device, with both fi ee brea thing and controlled nasal airflow. The average threshold for perception of nasal resistance was 0.383 Pa/cm(3)/s at baseline. After histamine applica tion, there was a significant decrease in nasal cross-sectional area (p = 0 .0001), associated with a decrease in nasal airflow (r = 0.6). The average threshold of perception increased to 1.373 Pa/cm(3)/s (p < 0.0001). When na sal airflow was controlled at the baseline rate, the threshold of perceptio n improved to 0.638 Pa/cm(3)/s (p = 0.024). These findings indicate that na sal congestion causes a reduction in both nasal airflow and the perception of resistance to nasal breathing. The ability to detect nasal airway impair ment is improved with increased nasal airflow. An improved understanding of the physiology of the subjective perception of nasal patency may lean to i nnovative methods for the treatment of nasal obstruction.