FROM BRONCHIOLITIS TO ASTHMA

Review of the literature shows that bronchiolitis is one of the chief factors leading to asthma in infants and young children. The risk of a broncho-obstructive syndrome following acute bronchiolitis sufficiently severe to have required hospitalisation is 75 % after two years, 42 % after 5 years and 22 % after 8-10 years. Whether clinically evident or not, functional disturbances concern the majority of parameters investigated. Bronchial hyperreactivity, which can persist for 5 to 10 years after the initial viral infection, may be maintained and/or worsened by new viral infections. Other factors also play a role: genetic predisposition to asthma or allergy, passive smoking, precarious socio-economic circumstances, prematurity, delayed growth, transitory tachypnea of the newborn, and bronchodysplasia. The role of bacterial infection at the time of severe and/or prolonged bronchiolitits, present in 50 per cent of cases, has not yet been adequately evaluated.