Childhood Allergies More Prevalent Worldwide
International study finds steepest prevalence increase among children ages 6 to 7
FRIDAY, Aug. 25 (HealthDay News) -- The prevalence of childhood allergies has increased worldwide since 1991, especially in children ages 6 to 7, according to a study published in the Aug. 26 issue of The Lancet.
Between 2002 and 2003, Innes Asher, M.B.Ch.B., of the University of Auckland in Auckland, New Zealand, and colleagues surveyed the parents of 193,404 children ages 6 to 7 years from 66 centers in 37 countries and 304,679 children ages 13 to 14 years from 106 centers in 56 countries. They compared the results to those of the 1991 International Study of Asthma and Allergies in Childhood.
The researchers found that increases in prevalence outnumbered decreases at most centers, and observed the highest increases for eczema in the younger children and hay fever in both age groups. Among children ages 13 to 14, the investigators found that asthma symptoms more commonly decreased in areas where asthma prevalence had previously been high. They identified Asia-Pacific and India as the only regions where increases in prevalence of all three disorders outnumbered decreases in both age groups.
"In almost all centers, there was a change in prevalence of one or more of the disorders over time," the authors conclude. "Although changes in mean annual prevalence to the order of 0.5 percent might sound small, such changes could have substantial public-health implications, especially since the increases took place most commonly in heavily populated countries."