Prevalence and Characteristics of Itch in Patients with Parkinson's Disease

Patients with Parkinson's disease (PD) report increased pain sensitivity. Previous studies have found a larger area of itch hypersensitivity in PD patients, suggesting altered central processing. High levels of cutaneous α-synuclein, correlated with small-fibre neuro-pathy, may be another mechanism of pruritus in these patients. This study aims to characterize itch in PD patients without pruritic cutaneous disease and correlate it with disease characteristics. A total of 100 PD patients were surveyed using a modified numeric itch scale. Patients reporting chronic itch were included in the itch+ group. Demographic data were collected by retrospective chart review. In all, 41% of patients (41/100) reported itching. There was a significant correlation between PD duration and 24-h average itch severity (0.491, p = 0.002). Itch is common among PD patients, with a positive correlation between PD duration and itch severity. Further research is needed to study larger cohorts and elucidate underlying pathomechanisms. Itch is often an underappreciated symptom of PD with potentially significant quality-of-life implications. This is among the first studies to characterize the prevalence and characteristics of itch in a substantial cohort of PD patients and how they may be related to other disease characteristics.