Perceptual and physiologic effects of histamine challenge on nasal breathing

The purpose of this study is to determine the effect of histamine- induced nasal congestion on nasal airflow and the perception of externally applied resistance to nasal breathing. Nasal cross-sectional area and nasal airflow during free breathing were measured in 15 adult subjects before and after histamine challenge. The threshold for perception of resistance to nasal breathing was determined using a dynamic perturbator device, with both free breathing and controlled nasal airflow. The average threshold for perception of nasal resistance was 0.383 Pa/cm³/s at baseline. After histamine application, 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/cm³/s (p < 0.0001). When nasal airflow was controlled at the baseline rate, the threshold of perception improved to 0.638 Pa/cm³/s (p = 0.024). These findings indicate that nasal congestion causes a reduction in both nasal airflow and the perception of resistance to nasal breathing. The ability to detect nasal airway impairment is improved with increased nasal airflow. An improved understanding of the physiology of the subjective perception of nasal patency may lead to innovative methods for the treatment of nasal obstruction.