COLD DRY AIR-INDUCED RHINITIS - EFFECT OF INHALATION AND EXHALATION THROUGH THE NOSE

Ten subjects with a history of cold air-induced nasal symptoms partici pated in a randomized two-period crossover study to evaluate the occur rence and magnitude of the reaction induced by inhalation and exhalati on of cold dry air through the nose. The protocol involved breathing o f either warm moist or cold dry air for 45 min at resting breathing ra tes. The nasal response was quantified by determining the amount of pr oduced secretions as well as by measuring histamine and N-alpha-p-tosy l-L-arginine methyl (TAME) esterase activities in recovered nasal lava ge fluids. Symptom scores were obtained. Warm moist air did not increa se symptoms nor did it result in any significant changes in secretions or mediator levels. Compared with baseline, cold dry air induced sign ificant rhinorrhea and increased both secretion weights (9.6 +/- 1.3 v s. 28.1 +/- 6.5 mg; P = 0.01) and the levels of histamine (3.9 +/- 1.2 vs. 10.6 +/- 2.7 ng/ml; P = 0.02) and TAME esterase activity (3.1 +/- 0.8 vs. 7.0 +/- 2.0 counts . min(-1) . 10(-3); P = 0.01). We conclude that bidirectional nasal breathing of cold dry air results in a react ion that is qualitatively similar to that induced when air is only inh aled through the nose and exhaled through the mouth.