Airway hyperreactivity and a history of clinical manifestations of asthma in childhood.

The relationship between airway hyperreactivity and a history of the clinical manifestations of asthma was investigated in 54 children between the ages of 8 and 12. Airway reactivity was assessed by measuring the change in pulmonary function following the hyperventilation of subfreezing air. Clinical manifestations of asthma were assessed by a standardized questionnaire regarding lower respiratory symptoms and by medical records review. The subjects were participating in a study of the sequelae of bronchiolitis; 25 had seen a physician for mild bronchiolitis during the first 2 years of life, and the remainder had not. Airway hyperreactivity was demonstrated in 8 of the 54 children and correlated with use of medication for asthma in the 2 years before pulmonary testing and positive parental response to the question, "Does your child wheeze apart from colds?" Airway hyperreactivity did not correlate with a history of other respiratory symptoms or with a history of physician-diagnosed wheezing or asthma. No questionnaire or chart review item identified over 50% of the children with reactive airways, and most subjects identified by each of the items did not demonstrate hyperreactive airways. These data suggest that airway reactivity is only weakly associated with a history of the clinical manifestations of asthma in childhood, in part because children with clinically inactive asthma do not consistently demonstrate airway hyperreactivity and in part because many children with hyperreactive airways have never had respiratory symptoms.