Exercise-induced change of nasal resistance in asthmatic children

Exercise-induced change of nasal resistance and forced expiratory volume in 1 second (FEV1.0) were studied in 30 asthmatic children and seven normal children. Exercise-induced asthma (EIA) was diagnosed in 19 (63%) of the 30 asthmatic patients. Unilateral complete nasal blockage after exercise (exercise-induced nasal obstruction [EINO]) was found in nine (30%) of the 30 asthmatic patients. A marked decrease in nasal resistance took place immediately or 4 minutes after exercise in all cases. EIA is most severe 5 minutes after exercise, and EINO took place 14 or 19 minutes after exercise. The seven normal children had neither EIA nor EINO. The pathophysiologic relationship between EIA and EINO is discussed.