Young children with common ear, nose, and throat issues may be at increased risk of autism or demonstrable autism traits, according to new research published today.
The findings, published in BMJ Open, could help with early identification and treatment and may improve their quality of life. The findings could also potentially identify some of the origins of autism, the researchers say.
Previous research as suggested that some ENT conditions may have a role in the development of autism. However, most of this evidence is based on health records, which may be biased as parents of children with suspected autism may be more likely than other parents to seek medical help for their offspring.
To avoid potential bias, the researchers – from Aston University, Birmingham, UK, and the University of Bristol, UK, – examined data from the long-term Children of the 90s study, also known as the Avon Longitudinal Study of Parents and Children (ALSPAC), which has tracked the health of more than 14,000 children since birth and that of their parents from the early 1990s onwards.
This study is based on comprehensive data for more than 10,000 young children who were closely monitored during their first four years.
Their mothers completed three questionnaires when their children were aged 18, 30, and 42 months, which were designed to record the frequency of nine different signs and symptoms relating to the ear, nose, and throat as well as any hearing problems.
They also completed three further questionnaires when their children were just over three, nearly six, and nine years old, which focused on speech coherence, social and communication issues, repetitive and abnormal behaviours, and sociability. A diagnosis of autism was confirmed from educational records and parental feedback, among other sources.
Adjustments were made for 10 potentially influential environmental factors: early or late birth; sex; number of mother’s previous pregnancies resulting in a live or stillbirth; breast feeding; postnatal depression; mother’s educational achievements; mother’s smoking at 18 weeks of pregnancy; mother’s belief in her own agency; child’s exposure to environmental tobacco smoke at 15 months; child’s attendance at a crèche/other day care by the age of 30 months.
In total, 177 children had a probable diagnosis of autism, of whom 139 were boys and 38 girls. Those with autism traits were defined as the 10% of the sample with the highest trait scores.
Early evidence of breathing through the mouth, snoring, ear pulling or poking, reddened and sore ears, worse hearing during a cold, and rarely listening were more associated with high scores on each of the four autism traits, and with a diagnosis of autism.
Pus or sticky discharge from the ears was also associated with autism and with poor coherent speech.
There were strong associations when the child was aged 30 and 42 months: youngsters with high scores on autistic traits at 30 months had more ENT signs. Autism was significantly associated with all signs except for symptoms of sleep apnoea.
Factoring in the 10 environmental features made little difference to the results.
However, the researchers say these ENT signs and symptoms are very common in childhood and most children who experience them do not go on to be diagnosed with autism.
For example, of the group of about 1,700 children who snored at age 30 months, 1,660 were not later diagnosed with autism.
The researchers acknowledge their study had limitations, including the lack of ethnic diversity among the Children of the 90s participants and the fact that children were not examined consistently to determine a diagnosis of autism. Instead, there was a strategy to assess the probability of a diagnosis using a variety of different sources.
Despite these, they say the associations they found “may be important because (1) these ear and respiratory signs may be early markers of increased risk of autism, (2) they may inform the origins of autism, or (3) they may highlight co-occurring conditions that if treated may lead to a better quality of life for children with autism”.
They said: “This study adds to the evidence that, compared with a typical population of the same age, early ear and upper respiratory symptoms are more common in those subsequently diagnosed with autism or with extreme levels of autistic traits.”
However, they add that it is not possible to determine if these ENT conditions have a causal role in the development of autistic traits or are related to an unmeasured factor.
“One possibility, for example, could be the consequence of the increased prevalence of minor physical anomalies in individuals with autism, including anatomical differences in the structure and/or positioning of the ear, with such differences in ear morphology increasing the risk of ENT conditions,” they write.
Hall A, Maw R, Iles-Cavan Y t al. Associations between autistic traits and early ear and upper respiratory signs: a prospective observational study of the Avon Longitudinal Study of Parents and Children (ALSPAC) geographically defined childhood population. BMJ Open 25 April 2023; doi: 10.1136/bmjopen-2022-067682
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