Does day care, preschool, etc. have an effect on children developing allergies or asthma?

According to studies conducted by researchers at UCSF as well as one held by a group of MD’s posted on the Journal of Asthma webpage, daycare and preschool attendance does not boost the risk of asthma and in many cases, may lower it as the researchers with the Journal of Asthma observed a 34% decrease in the odds of children between the ages of 3-5 developing asthma if they regularly attended a childcare facility.