title: Risk of Parkinson's Disease Among Patients with Psoriasis: A Systematic Review and Meta-analysis.
abstract: BACKGROUND
  Patients with psoriasis might be at a higher risk of developing Parkinson's disease (PD) as a result of the detrimental effect of chronic inflammation on the neuronal tissue. This meta-analysis aimed to investigate this risk by comprehensively reviewing all available data.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of cohort and case-control studies that reported relative risk, hazard ratio, odds ratio, or standardized incidence ratio comparing the risk of PD in patients with psoriasis versus subjects without psoriasis. Pooled risk ratio and 95% confidence interval (CI) were calculated using random-effect, generic inverse variance methods of DerSimonian and Laird.
  
  
  RESULTS
  Three retrospective studies and one case-control study met our eligibility criteria and were included in this meta-analysis. The pooled risk ratio of PD in patients with psoriasis versus participants without psoriasis was 1.38 (95% CI, 1.15-1.66). The statistical heterogeneity was low with an I (2) of 35%.
  
  
  CONCLUSIONS
  Our meta-analysis demonstrated a statistically significant increased risk of PD among patients with psoriasis.
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, Mayo Clinic, Rochester, MN, USA; Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Patompong
authors.initials: P
authors.lastname: Ungprasert
authors.affiliation: Department of Internal Medicine, Division of Pulmonology and Critical Care Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Narat
authors.initials: N
authors.lastname: Srivali
authors.affiliation: Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.
authors.forename: Wonngarm
authors.initials: W
authors.lastname: Kittanamongkolchai
keywords: Epidemiology; Parkinson's disease; psoriasis; risk factor