Atopy and pulmonary function abnormalities in children with a history of acute bronchiolitis.

To assess the relationship between acute viral bronchiolitis and subsequent development of asthma, we studied retrospectively 97 index children, aged between 9 and 14 years, and 52 controls. The bronchiolitis group showed significantly lower values for mean expiratory flow at 50% of vital capacity (MEF50) higher incidence of atopy, and were more sensitive to methacholine than were controls, even if they had not shown recurrent wheezing episodes. It is suggested that an increased incidence of atopy, bronchial hyperresponsiveness, and reduced expiratory flows may be detectable in children with a history of acute bronchiolitis, regardless of the fact that they did not develop subsequent clinical symptoms suggestive of bronchial asthma.