Early childhood allergen avoidance reduces asthma onset by 50% in at risk children
In a major study entitled the Canadian Childhood Asthma Primary Prevention Study published in the Journal of Allergy and Clinical Immunology (2005;116:3-14) it was shown that early allergen avoidance for high risk infants reduced the onset of asthma by 50%. This controlled study involved 545 infants who were considered to be high risk for asthma (one parent with asthma or two parents with other allergic diseases). Half of the group used allergen avoidance from six months before birth and for one year after birth. The other group received usual care. The allergen avoidance included measures to control exposure to house dust mite, pet avoidance, elimination of environmental tobacco smoke and breast feeding or whey formula.
When the children were 7 years old they were examined with the following findings. The pediatric allergist doing the examination found asthma in 14.9% of the children in the allergen avoidance group and asthma in 23% of the control. When asthma was defined as wheezing without a cold plus bronchial hyperresponsiveness, 12.9% of the intervention group had asthma while 25% of the control had asthma.
The study clearly showed that measures instituted before birth and continued through the first year of life can reduce the prevalence of asthma in high risk children. Follow-up is scheduled when the children are 11 to 12. This study is more compelling evidence that parents of asthma at-risk children and the newborn children themselves should use allergen avoidance measures such as dust mite controls, pet avoidance, elimination of ETS and breast feeding or use of whey formula.