Effects of elevated intranasal temperature on subjective and objective findings in perennial rhinitis.

The effects of elevated intranasal temperature on symptoms and signs of perennial rhinitis were studied in 78 patients by a double-blind, randomized, placebo-controlled clinical trial. Patients were subjected to two treatments separated by a 1-week interval. Each treatment consisted of three 30-minute sessions, during which the patient's intranasal temperature was raised by inhalation of saturated hot air (42 degrees C to 44 degrees C). Subjective response was recorded on a daily symptom score card during the week following treatment. Nasal patency was determined before and after treatment by measuring maximal nasal expiratory and inspiratory airflow and by measuring the area covered with vapor formed by the exhaled air on a plate. Highly reproducible results were obtained by using these three objective methods. Elevation of intranasal temperature resulted in amelioration of rhinitis symptoms and in objective evidence of increased nasal patency in a significant percentage of patients compared to the placebo-treated group.