Increase in Allergic Sensitization in Schoolchildren: Two Cohorts Compared 10 Years Apart.

Background: Time trends of incidence of allergic sensitization are unknown and recent trends of prevalence and risk factors are lacking.

Objective: To estimate the incidence, prevalence, remission, risk factors, and time trends for allergic sensitization among schoolchildren followed from age 7 to 8 years to age 11 to 12 years.

Methods: In 2006, all children in grades 1 and 2 aged 7 to 8 years in 2 municipalities in northern Sweden were invited to a questionnaire survey and to skin prick testing to 10 common airborne allergens.