Utilization of Skin Punch Biopsy for the Diagnosis of α‐Synucleinopathy in Clinical Practice

Background Skin punch biopsy has been investigated as a minimally invasive tool to aid in the diagnosis of idiopathic Parkinson's disease (IPD) via detection of cutaneous phosphorylated α‐synuclein. The use and impact of this tool in clinical practice has not been well‐characterized. Objective To understand the utilization of skin punch biopsies for diagnosis and management of α‐synucleinopathy within a large medical system. Methods Three hundred charts of patients who underwent skin punch biopsy were reviewed. Of these, 149 (49.7%) met criteria for analysis (concern for α‐synucleinopathy, age over 40). Demographic data, outpatient neurology and primary care notes, and imaging results were reviewed alongside biopsy results. Results Of 149 biopsies, 70% (N = 105) were positive in at least one skin sample. There was no statistically significant relationship between any pre‐biopsy symptom and a positive result. Most patients identified as white (N = 124, 83%) and non‐Hispanic (N = 131, 88%). The sex distribution was roughly equal (52% male, 48% female). While most tests were ordered for IPD or an unspecified primary parkinsonism, other clinical concerns included dementia with Lewy bodies (N = 41, 28%) and multiple system atrophy (N = 6, 4%). Only 4% of biopsies (N = 6) were ordered by movement disorders specialists. Results changed or strengthened diagnosis in 52% of cases and changed management in 60% of cases. Conclusions Skin punch biopsies are being used broadly with impactful results. However, there appears to be potential disparity in access to this test. Further research is required to inform clinical guidelines and promote equity in the use of this novel biomarker.