Is the Exhaled Nitric Oxide in Infants a Predictive Marker of Asthma ? (NOnourisson)

Background:

It seems that in the infants and the young children, the increase of the Exhaled Nitric Oxide (eNO) is in connection with: (1) the risk of developing respiratory symptoms; (2) the risk of family and personal atopy; (3) the intensity of the respiratory symptoms; (4) the risk of passage of recurrent wheezing to asthma; (5) and contrary to the fact that the investigators noticed at the child's a positive relation with the environmental tobacco smoke

Objective: the investigators objective is to bring to light that the rise of the eNO, a non invasive biomarker of the bronchial inflammation, would be a risk factor expected from passage of recurrent wheezing of the infant and the young child (of less than 36 months old) towards the asthma of the child.Methods: Once the diagnosis of recurrent wheezing established, the investigators estimate by questionnaire the severity of the asthma, the personal and familial atopy, the collection of the environmental data. After allergic exploration (skin tests and assay of serum total and specific IgE, complete blood count), the eNO is measured by an off-line tidal breathing method using a chemiluminescence NO analyzer. Annually, a questionnaire will be send to families to appreciate the persistence or the remission of the asthma. After a simple descriptive analysis of the population and a multifactorial descriptive analysis, the investigators shall look for the connections between the rise of the eNO and the various clinical, biological and environmental parameters known to influence the variations of this marker. Then the investigators shall select a set of explanatory variables for a multivariate analysis by a logistic regression step by step.