[Bronchial reactivity in clinically symptom-free adolescent patients with asthma]

More than half of the pediatric asthma population will become symptomfree during adolescence. We evaluated non-specific airway reactivity by cold air challenge in 42 symptomfree asthma patients, age 8 to 18 years, one year after termination of their anti-asthmatic medication. Twenty-one patients showed a normalized bronchial reactivity, 16 were found to be hyperreactive, and 5 presented with a borderline response. When compared to the normoreactive group, the hyperreactive subjects showed the following statistically significant differences: 1) more allergy by RAST and history (16/16 vs 14/21, p less than 0.05); 2) a significant reduction of mid- and endexpiratory flowrates in baseline lung-function measurements (% pred); maximum expiratory flow at 50% vital capacity: 75% vs 96%, p less than 0.01; maximum expiratory flow at 25% of vital capacity: 71% vs 102%, p less than 0.005). In conclusion, more than one third of our clinically symptom-free patients showed persisting bronchial hyperreactivity; 50% presented with a normalised bronchial response.