Is prevention of allergy and asthma possible?

Allergy and asthma are common diseases today. Ways to stop the ongoing increase in incidence of these diseases are highly desired. In this review the scientific basis for allergy and asthma prevention is discussed. Results: Although secondary preventive measures are generally regarded as important, the views regarding the possibility of primary prevention vary. There is today only weak evidence that breastfeeding may reduce the risk of developing allergy, and if it does the effect is limited in degree and duration. There is some evidence that prolonged breastfeeding reduces the risk of developing asthma, at least in allergy-risk infants. There is also some evidence indicating that withholding solid foods in children at risk may have a beneficial effect. A dose-dependent risk of becoming sensitized to house dust mite and pet animal allergens has clearly been shown, but to what extent this sensitization is combined with asthma or clinical allergy is less well elucidated. Passive smoking increases the risk of wheezing problems and the indoor environment in damp houses seems to act synergistically with passive smoke. Conclusion: Primary prevention is rarely possible, but the risk of developing asthma and allergy may to some extent be reduced by taking certain measures, such as avoidance of tobacco smoke and damp houses. Breastfeeding seems to reduce the risk of wheezing, but as allergy-preventive measures, breastfeeding and avoiding pet animals have only marginal effects.