title: Prevalence and characteristics of psoriatic arthritis in Chinese patients with psoriasis.
abstract: BACKGROUND
  The prevalence and clinical characteristics of psoriatic arthritis (PsA) in patients with psoriasis vary widely in different countries and studies on Chinese population are rarely reported.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the prevalence and clinical characteristics of PsA in a Chinese population of patients with psoriasis.
  
  
  METHODS
  A large cross-sectional observational study was conducted in our outpatient dermatology department and consecutive psoriatic patients were evaluated for PsA according to Classification of Psoriatic arthritis (CASPAR) criteria. Demographic and medical parameters were recorded.
  
  
  RESULTS
  Among 1928 patients with psoriasis, 112 patients (5.8%) had PsA, of which 92% was newly diagnosed. Oligoarthritis (48.2%) was the most common manifestation pattern, followed by spondylitis (26.8%), polyarthritis (19.6%) and classic distal interphalangeal (DIP) arthritis (5.4%). Enthesitis was present in 26.8% and dactylitis in 13.4% of the patients. Compared with patients without PsA, patients with PsA had more severe skin disease (mean PASI 9.7 vs. 6.0), higher frequency of nail changes (46.4% vs. 21.0%) and scalp involvement (90.2% vs. 76.4%).
  
  
  CONCLUSIONS
  The findings are consistent with a low prevalence of PsA among patients with psoriasis in Asia and confirm a high percentage of undiagnosed cases with active arthritis among PsA patients in dermatologist's office. Dermatologists should screen for PsA in their patients, especially those with risk characteristics and early signs.
authors.affiliation: Shandong Clinical College of Skin Diseases, Anhui Medical University, Jinan, Shandong, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: L
authors.initials: L
authors.lastname: Qu
authors.forename: H
authors.initials: H
authors.lastname: Tian
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
authors.forename: J
authors.initials: J
authors.lastname: Peng
authors.forename: X
authors.initials: X
authors.lastname: Yu
authors.forename: C
authors.initials: C
authors.lastname: Yu
authors.forename: Z
authors.initials: Z
authors.lastname: Pei
authors.forename: G
authors.initials: G
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Shi
authors.forename: F
authors.initials: F
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: F
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000328:Adult; D015535:Arthritis, Psoriatic / Q000175:diagnosis / Q000453:epidemiology*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence