Skip to main content

A Skin Test for Parkinson’s? What You Need to Know

Patient on bed speaking to a doctor

Parkinson’s disease (PD) has always been defined by its symptoms, but we now can also find key indications of the disease through biological tests – a whole new era for PD and diseases like it. For example, a skin test was able to reliably detect Parkinson’s disease, according to recent data published in The Journal of the American Medical Association's (JAMA) Network. The skin test is commercially available (meaning your doctor can order the test) and is being used to contribute to diagnoses by some clinicians, though whether the test would be helpful for you is a decision for you and your care team, ideally with input from a movement disorder specialist.  

For now, perhaps the most important thing about this skin test, along with other similar biomarker tests, is the pivotal role it will play in research, empowering highly targeted clinical trials for new treatments and delivering new insights about the biology of Parkinson’s disease. These trials can now confirm biology when selecting participants, ensuring we put the right people in the right trials. Trials can also begin to test therapies that precisely target different aspects of Parkinson’s biology, opening new avenues for testing both symptom-relieving therapies and even treatments that could change the course of the disease. If you are interested in getting a test like this, please also consider the role you can play in clinical trials that urgently need you and that could dramatically accelerate progress toward next-generation treatments for PD. Keep reading for links that can you get started. 

News like this inspires a lot of questions in the Parkinson’s community; here are answers to a few of the more prominent ones. 

What does the test show?  

Parkinson’s disease is associated with the accumulation of a misfolded protein called alpha-synuclein in brain and body cells. As of 2023, we can for the first time detect that dysfunctional biology in the living body, rather than only posthumously, helping propel us into a new “biological era of Parkinson’s.”  

According to the recently published paper, the skin biopsy detected misfolded alpha-synuclein in skin samples from 92.7 percent of confirmed PD patients in the study. 

It also detected the misfolded synuclein in people with related neurodegenerative conditions, like Dementia with Lewy Bodies (DLB) and multiple system atrophy (MSA). 

These results are similar to the Synuclein Seeding Amplification Assay (SAA), an effort funded by The Michael J. Fox Foundation (MJFF), which can detect misfolded alpha-synuclein in spinal fluid obtained through a spinal tap. 

The growing number of biomarker tests showcases the promise of the biological era of Parkinson’s, helping us expand our understanding of the disease and how to treat it. 

Is this test for you?  

It’s important to take stock of what this test can and cannot do. As Rachel Dolhun, MD, DipABLM, senior vice president of medical communications at The Michael J. Fox Foundation (MJFF) explained in our Ask the MD blog about this test last year, “When considering any test, you should ask your doctor what it can and can’t tell, any risks, and, most importantly, if and how it will direct treatment, care or prognosis.”  

She added, “If the results, either positive or negative, won’t affect what you and your doctor do, then it may not be worth the time and cost.” 

The skin test, just like the SAA test, gives a positive or negative result, showing misfolded alpha-synuclein is either present or not present. This is in contrast to “quantified” biomarkers that provide deeper information about disease states (think of a cholesterol test that can give detailed results about levels of “good” and “bad” cholesterol, helping your doctor tailor a medication and lifestyle approach to reduce your risk of major heart disease). The Michael J. Fox Foundation is funding and coordinating research efforts to advance Parkinson’s biomarkers to be able to deliver similarly “quantified” results in PD. The goal is to develop a test that could, for example, reflect how much dysfunctional alpha-synuclein is present, perhaps opening insights into how the disease progresses over time.  

In a recent Wall Street Journal article about the skin biopsy, one clinician was able to use the test to solidify their diagnosis of a patient, though the diagnosis still came primarily from clinician’s observation of symptoms.  As of now, the test would not play a role in directing treatment for people who have already been diagnosed with PD or who may be at risk. 

Mark Frasier, PhD, chief scientific officer at MJFF, elaborated, “The field still has work to do on the role biomarker tests can play in clinical care, but the implications for research – and what that means for people and families with Parkinson’s down the line – are enormous.” 

What does the test mean for research? 

Clinical trials rely on participants with confirmed cases of PD. However, not everyone with diagnosed PD tests positive for misfolded alpha-synuclein, and there are other diseases that can look like Parkinson’s but aren’t. Confirming that the protein is misfolding, through any test, allows for more selective clinical trials. With biomarker tests, trials can target disease biology that researchers objectively know is present, ensuring they choose the right people to participate. If the drug doesn’t work, we will no longer have to wonder if we were simply testing it in the wrong people — a challenge that has vexed modern Parkinson’s drug development. 

The recent wave of biomarker tests allows trials to narrow participants to those they are sure a treatment could help, if successful. After all, there are multiple therapies in development targeting misfolded alpha-synuclein. 

This is a unique moment in research, and your participation has the chance to supercharge it. The Michael J. Fox Foundation offers many ways to get involved, ranging from finding trials to participate in through our Fox Trial Finder to taking a smell test to see if you are at-risk for Parkinson’s.  

These efforts have the ability to change the research landscape, and your buy-in moves them forward.  

We use cookies to ensure that you get the best experience. By continuing to use this website, you indicate that you have read our Terms of Service and Privacy Policy.