A recent study has found that there may be an overlap between the skin condition eczema and Autism spectrum disorder (ASD).

The findings were published in Translational Psychiatry and suggest that there is an overlap between eczema and neurodevelopmental conditions like ASD that would indicate the need for further investigation.

Eczema is a common skin condition where the skin becomes red, inflamed, itchy or even hyperpigmented. It's also known as atopic dermatitis and is a chronic condition also often associated with allergies.

ASD is a developmental disorder with a range of behavioral, social and communication enhancements and challenges, and the study from the University of Sydney suggests that children who have ASD and who also have eczema are more likely to have worse symptoms.

Dr. Adam Guastella is the Michael Crouch Chair in Child and Youth Mental Health at the University of Sydney. He is also the study author and said,

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“We have long known that children with neurodevelopmental conditions often have a higher rate of eczema and allergies. There has been limited research to show whether having eczema and atopic diseases is also linked to more severe symptoms of neurodevelopmental conditions. Understanding this link better may provide leads into detection and intervention opportunities that can support both conditions.”

He also said,
“We have recently developed a model that highlights many of the co-occurring molecular features of autism and eczema and the evolutionary significance of the skin-brain connection. There is growing research about how the skin and brain co-develop and are subject to similar genetic and environmental factors that may drive the development of both. This idea has been summarised in a paper published in Molecular Psychiatry. Interestingly, we argue that the skin may provide useful insights that can also tell us about brain development.”
The study looked at the data from 140 children who were about 6 years old and had ASD. Atopic conditions like asthma, allergies, hay fever and eczema were found in 47 of the 140.

Dr. Guastella and his team found that children who presented with atopic comorbidities tended to have more severe autism symptoms present. They used the Autism Diagnostic Observation Schedule to measure these symptoms. Dr. Guastella said that the findings show an interesting relationship between skin conditions and autism that warrants more investigation.

“Having eczema (or atopic disease broadly) more than doubled a child’s chance of scoring on the severe end of autism symptoms and social difficulty symptoms, as rated by clinicians,”
He also said that it seemed that children with eczema in particular seemed to have more of the severe neurodevelopmental delay symptoms and finding out why that is may lead to earlier detection opportunities. Earlier detection and support may improve developmental processes for children.

The link between the atopic conditions and severity of autism symptoms could be 'incidental' as the main limit of the study was the cross-sectional nature of the data, but more research would likely continue to show stronger correlation.

Considering the skin is the body's largest organ, it stands to reason that it acts as an indication of what is going on with someone on a larger, wider scale.