[Environment and asthma in children: controversies].

The increase in asthma prevalence over the past 20 years could be due to modification of exposure to environmental factors (environmental theory) or to the lost of protective factors (hygienist theory). Among environmental factors this paper reviewed the controversial role of exposure to house dust mite (HDM). If exposure to HDM is deleterious in asthmatics known to be sensitised to this allergen, the effect of HDM exposure on asthma incidence has been challenged recently, based on longitudinal studies showing no correlation between level of exposure to HDM and asthma incidence.

[Future prospects in the management of cystic fibrosis].

Basic and clinical research in cystic fibrosis have led to several new hypothesis to improve the management of the disease. The numerous tracks for new therapies may be explained by the lack of firm patho-physiological explanations for the disease and of knowledge of the best targets to get a significant improvement of the patients. After initial great hopes, there has been important limitations and slow down of gene therapy, imposing to go back to research programs on new vectors.

[Prevention of respiratory syncytial virus infection by SYNAGIS (palivizumab)].

Infection with respiratory syncytial virus is frequent but most often benign. The serious forms of the illness, which make necessary hospitalisation or care in an intensive Care Unit, appear in infants of less than 6 weeks and especially in those with underlying pathologies, prematurity, congenital cardiopathies or chronic respiratory illnesses. Palivizumab (SYNAGIS) is mouse humanized monoclonal antibody which is used for prevention by monthly injections before and during the epidemic period.

[Differential diagnosis of asthma in infants and young children].

Although when an infant or a young child presents with persistent or recurrent wheezing, the probability of asthma is high, one must remain very careful in order not to miss an other etiology. Except for the chest X ray with inspiratory and expiratory studies that is mandatory, the other evaluations should be based on a careful interview and clinical examination. Fiberoptic bronchoscopy may be indicated each time there is a doubt on foreign body aspiration or tracheobronchomalacia.