Jennifer Thornton
Background: Parkinson's disease (PD), dementia with Lewy bodies, and related synucleinopathies lack validated prevention strategies, despite growing evidence that environmental and biological factors may contribute to disease initiation. Epidemiologic and mechanistic data increasingly implicate peripheral tissues as potential sites of early pathology. Dermatologic and ocular conditions—including rosacea, ocular rosacea, seborrheic dermatitis, cataracts, and melanoma—are associated with elevated PD risk and may provide accessible interfaces for early detection and intervention.
Methods: We propose a prevention-oriented, randomized trial enrolling individuals newly diagnosed with PD and individuals at elevated risk based on relevant dermatologic or ocular phenotypes. Participants would undergo standardized skin and ocular swabbing with DNA-based PCR assays to detect mites (e.g., Demodex and scabies) and associated microbes or pathogens. Demodex and scabies mites inhabit sebaceous and lymph-rich tissues, where they consume sebum and lymphatic material. Sebum has been shown to be altered in Parkinson's disease. Participants would be assigned to targeted vector and/or microbe eradication therapies or to standard-of-care control groups. Post-treatment resampling would confirm eradication. Longitudinal follow-up would include clinical assessments (motor and cognitive scales), biomarker evaluation (including cutaneous phosphorylated α-synuclein using tools such as the Syn-One biopsy), and repeat microbiological sampling. Neuroimaging may be incorporated where appropriate.
Results: The primary outcome is whether confirmed eradication of vectors and associated microbes correlates with stabilization, slowed progression, or prevention of synucleinopathy-related clinical and biomarker changes. Secondary outcomes include changes in skin and ocular biomarkers, α-synuclein burden, and longitudinal clinical trajectories. This framework is supported by epidemiologic observations, including reduced PD risk following lindane treatment for scabies, and mechanistic plausibility that mites may carry neurotoxic compounds, transmit microbes, or facilitate prion-like propagation. Additional support includes evidence that house dust mites exacerbate Alzheimer's-related pathology, overlap of Lewy body pathology between Alzheimer's and Parkinson's disease, and shared lymphatic drainage pathways between ocular tissues and the central nervous system, particularly relevant in ocular rosacea.
Conclusions: This Trial Design Forum advances a testable, closed-loop, prevention-focused paradigm integrating dermatologic, ocular, microbiological, and neuropathological markers to evaluate peripheral initiation hypotheses in synucleinopathies. By directly identifying, treating, and verifying eradication of potential vector-mediated contributors, this multidisciplinary framework offers a novel approach to prevention-oriented research in Parkinson's disease and related disorders.