Scientists at The University of Manchester have found small molecules contained in a substance secreted by the skin, known as sebum, that are responsible for a unique scent in people with Parkinson’s.

The results could lead to the development of an early diagnosis test for the neurodegenerative disorder. At present there are no definitive diagnostic tests currently available.

The research, which was led by scientists at The University of Manchester and funded by Parkinson’s UK and the Michael J. Fox Foundation, was recently published in the journal ACS Central Science.

Scientists already know that Parkinson’s can cause excessive production of sebum, a natural waxy, lipid-based bio fluid that moisturises and protects the skin. Joy Milne an Honorary Lecturer at The University of Manchester noticed that people with Parkinson’s had a distinct and different smell, which changed intensity as the condition progressed. She first noticed this smell in her husband Les, many years before he was clinically diagnosed with Parkinson’s.

Researchers at the University’s Manchester Institute of Biotechnology (MIB) used mass spectrometry to identify the molecular compounds that give the condition this unique odour. To figure out what makes this smell, at a molecular level, the team analyzed the volatile components from the sebum found on people who have been diagnosed with Parkinson’s. The odour of these components was double checked by Joy Milne.

The researchers collected sebum samples using gauze to swab the upper backs of more than 60 subjects, both with and without Parkinson’s. They then analysed the sample data and found the presence of hippuric acid, eicosane and octadecanal, which indicates the altered levels of neurotransmitters found in Parkinson’s patients, along with several other biomarkers for the condition.

By considering the levels of these molecules found in the test samples, the team has generated a model that can now identify and diagnose Parkinson’s at all stages of the condition.

Professor Perdita Barran, Professor of Mass Spectrometry in MIB, said: “Now we have proved the molecular basis for the unique odour associated with Parkinson’s we want to develop this into a test.

“This could have a huge impact not only for earlier and conclusive diagnosis but also help patients monitor the effect of therapy. We hope to apply this to at risk patient groups to see if we can diagnose pre-motor symptoms, and assist with potential early treatment.”

Professor David Dexter, Deputy Director of Research at Parkinson’s UK, said: “Finding changes in the oils of the skin in Parkinson’s is an exciting discovery that was sparked by a simple conversation between a member of the public and a researcher.

“More research is needed to find out at what stage a skin test could detect Parkinson’s, or whether it is also occurs in other Parkinson’s related disorders, but the results so far hold real potential. Both to change the way we diagnose the condition and it may even help in the development of new and better treatments for the 145,00 people living with Parkinson’s in the UK.”

Parkinson’s is a neurodegenerative disorder that leads to progressive brain cell death and extensive loss of motor function and, despite much research being conducted, there is still no diagnostic tests available on the market.

Dr Monty Silverdale, Consultant Neurologist and Honorary Senior Lecturer in Neuroscience at The University Manchester added: “We acknowledge this is a small study but it does open the door to the development of a non-invasive screening test for Parkinson’s, potentially leading to earlier detection for thousands of patients.”