The number of children being diagnosed with attention-deficit disorder, allergy and asthma is rising in the United States, and a new study found a possible link between the increases in these three conditions based on data from the United Kingdom.
As published in the scientific journal of the American College of Allergy, Asthma and Immunology, researchers from the University of Groningen in the Netherlands and the Boston University School of Public Health found an increased risk of ADHD in boys with a history of allergy or asthma.
Using UK study cohorts, the researchers studied 884 boys with ADHD and 3,536 boys without the disorder. Of the children with ADHD, 34% had asthma and 35% had an allergic disorder.
After adjusting for age and low birth weight or preterm delivery, the researchers found a history of asthma was associated with a 40% higher risk of ADHD and impetigo, and antihistamine drug prescriptions were associated with a 50% higher risk.
“Other exposures that were more common in [ADHD] cases than controls, though not independently, were cows milk intolerance and any prescription from the drug categories antiasthmatics, respiratory corticosteroids, topical steroids, antibacterials or antifungals,” the authors wrote.
The study suggests medications used to treat these conditions may be associated with an increased ADHD risk.
“Further research is needed to understand why there appears to be an increased risk of developing ADHD in children with allergy and asthma,” Gailen Marshall, MD, editor-in-chief of the Annals of Allergy, Asthma & Immunology, which published the study in its August issue, said in a news release. “Medications for these conditions far outweigh the risks, and can be life-saving in some conditions. Treatment should not be stopped unless advised by a board-certified allergist.”
According to the ACAAI, allergy and asthma often run in families. If both parents have an allergy, a child has a 75% chance of being allergic, compared with 10% to 15% for children of two parents without allergies. Allergists also know allergies and asthma are linked. An estimated 60% to 80% of children with asthma also have an allergy. While the cause of ADHD is unknown, this disorder is also thought to run in families.
Study abstract: http://bit.ly/132HDKf.