This artilce also appeared in the 2018, Volume 32, No. 3 issue of ARI's Autism Research Review International newsletter.
Children with food, respiratory, or skin allergies are significantly more likely to have an autism spectrum disorder (ASD) than children without allergies, according to a new study that adds to evidence implicating immune dysfunction in autism.
In the study, Guifeng Xu and colleagues reviewed data collected by the U.S. National Health Interview Survey between 1997 and 2016. Their analysis included nearly 200,000 children between 3 years and 17 years of age. Of these, 1,868 had an ASD diagnosis.
The researchers report that children with ASD were more likely to have food allergies (11.25% vs. 4.25%), respiratory allergies (18.73% vs. 12.08%), and skin allergies (16.81% vs. 9.84%) than children without ASD. The likelihood of having ASD more than doubled among children with food allergies compared to those without food allergies. Skin and respiratory allergies were also associated with elevated odds of having an ASD diagnosis, although to a lesser degree.
The researchers note, “The association between food allergy and ASD was consistent and significant in all age, sex, and racial/ ethnic subgroups.” However, boys with ASD were more likely than girls with ASD to have respiratory and skin allergies.
The researchers say it is interesting that the link between food allergies and ASD was the most robust, noting that the prevalence of both conditions has increased over the past two decades. They speculate, “Food allergy may involve alterations in the gut microbiome, allergic immune activation, and impaired brain function through neuroimmune interactions, which may finally affect the enteric nervous system and central nervous system leading to neurodevelopmental abnormalities.”
Commenting on the study in a separate article, autism specialist Christopher McDougle says, “From a clinical perspective, patients with ASD who are minimally verbal to nonverbal may be unable to describe the pain and discomfort they experience secondary to food allergy and subsequent inflammation in the gastrointestinal (GI) tract. Instead, their physical distress may manifest as irritability, aggression, and/or self-injury. It is important to underscore the need for healthcare professionals to conduct a thorough history and physical examination to rule out identifiable medical causes of aberrant behavior, including food allergy and secondary GI inflammation, before proceeding with treatments designed to reduce behavior problems.”
“Association of food allergy and other allergic conditions with autism spectrum disorder in children,” Guifeng Xu, Linda G. Snetselaar, Jin Jing, Buyun Liu, Lane Strathearn, and Wei Bao, JAMA Pediatrics, June 2018 (open access). Address: Wei Bao, Department of Epidemiology, College of Public Health, University of Iowa, 145 N. Riverside Dr., Room S431 CPHB, Iowa City, IA 52242, [email protected]
“Another step toward defining an immunemediated subtype of autism spectrum disorder,” Christopher J. McDougle, JAMA Pediatrics, June 2018 (open access). Address: Christopher J. McDougle, Lurie Center for Autism, Massachusetts General Hospital, Department of Psychiatry, Harvard Medical School, One Maguire Road, Lexington, MA 02421, [email protected]