An older couple listens to a medical professionalShare on Pinterest
Parkinson’s disease is currently commonly diagnosed through symptoms such as leg tremors. Morsa Images/Getty Images

Parkinson’s is the second most common neurodegenerative disease after Alzheimer’s, according to the Parkinson’s Foundation.

Yet, the vast majority of the 60,000 people in the United States diagnosed with Parkinson’s disease each year don’t know they have the disease until they have already started exhibiting symptoms.

A new test, however, could potentially lead to earlier detection and treatment of Parkinson’s.

Past research has shown that elevated levels of sebum, an oily secretion from the sebaceous glands under the skin, can serve as a marker for Parkinson’s.

Sebum is part of a class of high molecular weight lipids that are more prevalent among people with Parkinson’s, according to a study published in the JACS Au, an American Chemical Society journal.

In the study, researchers from the University of Manchester in the United Kingdom used cotton swabs to gather samples of sebum from the skin.

Using mass spectrometry, scientists were able to analyze the samples to identify individuals at high risk of Parkinson’s within 3 minutes.

Dr. Perdita Barran, a professor of mass spectrometry at Manchester and the lead study author, said in a press statement that the findings “take us closer to making a diagnostic test for Parkinson’s disease that could be used in clinic.”

In the study, sebum samples were gathered from the upper backs of 79 people with Parkinson’s and compared with a control group of 71 people. Concentrations of sebum are known to be highest in this part of the body.

The clinical study follows observational research involving Joy Milne, a person with hereditary Hyperosmia, or sensitivity to smells. Researchers working with Milne determined that she could correctly identify individuals with Parkinson’s disease simply by smelling the sebum that accumulated on their skin.

If the sebum swab test is proven effective in further clinical trials, it would be the first biomarker-based diagnostic test for Parkinson’s.

“This test has the potential to massively improve the diagnosis and management of people with Parkinson’s disease,” said Dr. Monty Silverdale, a neurologist, professor at Manchester, and the clinical lead author of the study, in a press statement.

Developing such a test is part of the core mission of the Michael J. Fox Foundation (MJFF), which provided funding for the research alongside the group Parkinson’s UK, according to Dr. Samantha Hutten, director of discovery and translational research for the foundation.

“MJFF-funded researchers worldwide are working urgently to develop innovative and non-invasive ways that may allow us to treat some of the most challenging and under-addressed aspects of Parkinson’s disease and diagnose people earlier,” Hutten told Healthline. “If we can detect the disease earlier, we hope this work could translate into ways to help identify those at risk for disease and we can intervene with therapies that hopefully will stop the disease process before symptoms arise or worsen.”

“Measuring Parkinson’s disease with an easy non-invasive method, like a skin-swab test, would be game-changing and may lead to improved insights in Parkinson’s care management, treatments, and ultimately, a cure,” she added. “We’re still in the early stages of innovation and the development of a diagnostic skin-swab test on a larger scale, but I’m energized by the possibilities.”

“This paper builds on previous work by this same group to establish lipid profiling in sebum as a biomarker for [Parkinson’s],” Dr. Natalie Diaz, a neurologist at the Pacific Movements Disorder Center at Pacific Neuroscience Institute in California, told Healthline. “They have previously been able to show that the composition of lipids in sebum using liquid or gas chromatography-mass spectroscopy can distinguish patients with [Parkinson’s] from controls.”

Diaz said the study seems to point to a rapid and inexpensive way to identify people who may have Parkinson’s. However, she said, “there is no clinical data available on the [Parkinson’s] patients enrolled into this study to understand if this rapid and inexpensive method is sensitive enough to identify [Parkinson’s] patients in the early, untreated stage versus those without [Parkinson’s].”

Also unclear, said Diaz, is whether the sebum swab test can be used to differentiate between people with Parkinson’s and those with other forms of degenerative neurological diseases that also are characterized by altered sebum levels.

Currently, Parkinson’s is most commonly diagnosed by a clinical examination where doctors look for common symptoms of the disease, particularly:

  • Tremors in the hands, arms, legs, jaw, or head.
  • Muscle stiffness where muscle remains contracted for a long time.
  • Slowness of movement.
  • Impaired balance and coordination, which sometimes leads to falls.

According to the Parkinson’s Foundation, early signs of Parkinson’s disease may include slight tremors, a decrease in the size of handwriting, loss of sense of smell, sleep disruptions, trouble walking or moving, constipation, a low or soft voice, a “masked” facial expression that often appears angry, tired, or depressed, dizziness or fainting, and being stooped or hunched over.