Can a child’s sense of smell be a sign of autism?

Can a child’s sense of smell be a sign of autism?

Children with autism spectrum disorder experience smells differently than children who do not have autism, according to a new study.

The research at the Weizmann Institute of Science in Israel used a device called an olfactometer to test 36 children and their sense of smell. Eighteen of the children had autism, 18 did not. The children were asked to smell both sweet smelling things like roses and shampoo, as well as, less pleasing smells such as rotten fish and sour milk.

Study leaders found that children without autism had the expected sniff response. They took a little longer in smelling the good smells and the minute they sniffed the unpleasant smells, their breathing changed noticeably. The response was quite intuitive and similar to what you would expect in adults.

That was not the case for children diagnosed with autism. Their breathing didn’t change when they smelled rotten fish or sour milk compared to the more pleasant smells. Their reaction was the same, no matter the smell.

“A diagnosis of autism spectrum disorder is made on a clinical basis using standardized tools and clinical observations,” says Dr. James Weedon, director of developmental pediatrics at Advocate Children’s Hospital in Park Ridge, Ill. “Information about differences in reactions to smells will not change how the diagnosis is made, but is an interesting insight into how the connections in the mind of a child with autism spectrum are functioning.”

For many years, differences in sensory reactions have been noted in children with autism as they often have either an exaggerated or limited response to sight, sound and touch.

“Parents need to keep in mind that many times sensory differences exist without the child having a diagnosis of autism spectrum disorder,” Dr. Weedon says. “If parents have concerns, they should consult their child’s pediatrician about the most appropriate strategies for evaluation and treatment interventions.”

More research is necessary in order to determine if using the smell test could be helpful in diagnosing autism in children sooner explains researchers.

“We know that most children with autism spectrum disorder have differences in their sensory processing, which may include how they react to and process information about odors,” Dr. Weedon says.

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  1. Fascinating study and very consistent with what we experience with one of our children on the spectrum. Their sensory perceptions in multiple senses are quite different than neurotypical children. I don’t know whether the sense of smell is lesser or greater, or if it is just that, “different”. I asked Temple Grandin about this when she was here locally at a college to give a visiting lecture. She is a women with ASD, who has successfully completed a masters degree and is employed full time, and has authored a number of books about autism based on her experiences. She commented that certain behaviors are related to autistic children seeking out strong odors, even unpleasant ones.

  2. My daughter has recently been diagnosed ASD, and this article helped me so much, to understand her eating habits. She only eats orange things. I didn’t even link the color with her diet until I read this article. Thank you!

About the Author

Evonne Woloshyn
Evonne Woloshyn

Evonne Woloshyn, health enews contributor, is director of public affairs at Advocate Children's Hospital. Evonne began her career as an anchor and reporter in broadcast news. Over the past 20 years, she has worked in health care marketing in both Ohio and Illinois. Evonne loves to travel, spend time with family and is an avid Pittsburgh Steelers fan!