[Asthma in infants and young children. Prevention, challenge of the 21st century?].

Many studies have been dedicated to the prevention of infant and childhood asthma in recent years. Primary prevention begins during intra uterine life (maternal smoke, diet, allergen exposure). During the first year of life, prolonged breastfeeding has been found to be a protective factor against the development of allergy and asthma. The role of infections and lifestyle is controversial and it is not clear whether these factors reduce or increase the risk of asthma. Environmental measures such as avoidance of tobacco smoke and reducing allergens exposure must be recommended to infants with high risk of asthma.