Food allergy prevalence increased from 3.4% to 5.1% between 1997 and 2011, while skin allergy prevalence more than doubled in the same time period. That means 1 in every 20 children will develop a food allergy and 1 in every 8 children will have a skin allergy. According to the CDC, respiratory allergies are still the most common for children younger than 18.
The new report, which looked at data from the National Health Interview Survey, found that skin allergies decreased with age, while respiratory allergies increased as children got older.
Both food and respiratory allergies also increased with income level, meaning richer families had higher rates of childhood allergies. Hispanic children had lower rates than non-Hispanic white and black children in the survey. The report did not look into the potential reasons for this.
Scientists are still trying to figure out where allergies come from, and why they're on the rise in the United States. Internal bacteria, genetics and environment may all play a role, says Dr. Edward Zoratti, head of the allergy and immunology division at Henry Ford Hospital in Detroit.
Image: Girl scratching her arm, via Shutterstock