BRONCHIOLITIS IN THE HISTORY OF THE ASTHMATIC CHILD

In a retrospective analysis of the history of 1,700 asthmatic children, 167 (9.8%) were found to have had bronchiolitis during the first 2 years of life. These 167 cases with asthma and bronchiolitis were matched against 215 selected cases of asthma without bronchiolitis. Both groups attended our Ambulatory Care Unit for Asthma. Data were collected from the clinical cards of the children. Asthmatics who had bronchiolitis were found to have an earlier onset of asthma (p < 0.001), earlier resolution of symptoms (p < 0.05 total; p < 0.01 females), and less evidence of atopy (p < 0.005). It is suggested therefore that the bronchial hyperreactivity in asthma following bronchiolitis may have different underlying mechanisms than in the typical atopic case, without preceding bronchiolitis. Long-term follow-up studies in infants with bronchiolitis are still necessary in order to clarify the process by which bronchiolitis predisposes to bronchial hyperreactivity and asthma. The consequences of the viral infection itself may lead to pathophysiological processes that promote bronchial hyperreactivity. On the contrary, an underlying condition of bronchial hyperreactivity could be the "primum movens" of the bronchiolitis itself.