The findings of a study in JAMA Network Open suggest an association between autism spectrum disorder and allergies — especially food allergies — in children.
Diagnoses of autism spectrum disorder have become more common since the turn of the century; the Autism and Developmental Disabilities Monitoring Network estimated that 1.46% of children in the United States have an autism spectrum disorder, up from 0.67% in 2000. Food and skin allergies, 2 common components of childhood immune system dysfunction, were more frequently reported between 1997 and 2011.
The investigators used data from the National Health Interview Survey gathered between 1997 and 2016, including children between ages 3 and 17 whose parents had indicated they had a food, respiratory, or skin allergy. In total, data on 199,520 children were analyzed, with 4.31% reporting a food allergy, 12.15% reporting a respiratory allergy, and 9.91% reporting a skin allergy, including eczema. Autism spectrum disorder was reported in 1868 children, or just under 1%.
Adjusted analyses reported an odds ratio (OR) of 2.29 (95% CI, 1.87-2.81) for food allergies in children with autism spectrum disorder. Less outstanding, although still significant, were the ORs for respiratory and food allergy, which were 1.28 (95% CI, 1.10-1.50) and 1.50 (95% CI, 1.28-1.77), respectively.
At least 2 previous studies reported a relationship between food sensitivities and autism spectrum disorder, while other research has focused primarily on respiratory and skin allergies. Understanding the cause of this relationship requires further research, but possible explanations have included T-cell imbalance and increased autoantibody production, among others.
The interpretability of these findings is limited by the self-reported nature of the National Health Interview Survey. Nonetheless, the researchers stated that their “findings warrant confirmation in prospective cohort studies.”
Xu G, Snetselaar L, Jing J, et al. Association of food allergy and other allergic conditions with autism spectrum disorder in children [published online June 8, 2018]. JAMA Network Open. doi:10.1001/jamanetworkopen.2018.0279