title: Baseline relationships between psoriasis and psoriatic arthritis: analysis of 221 patients with active psoriatic arthritis. Department of Veterans Affairs Cooperative Study Group on Seronegative Spondyloarthropathies.
abstract: OBJECTIVE
  To determine differences in disease onset, extent, and manifestations of psoriasis among patients with active, inflammatory psoriatic arthritis (PsA), and to examine relationships that may exist between psoriasis and PsA.
  
  
  METHODS
  Baseline demographic, clinical, and laboratory data were analyzed from 221 patients enrolled in a multicenter cooperative study, and relationships between measures of psoriasis and PsA were determined.
  
  
  RESULTS
  Mean percentage of body surface area (BSA) affected by psoriasis was modest (12+/-17), and mean severity of erythema, induration, and scaling was moderate (4.9+/-2.1 on a 0-9 scale). Spanish Americans tended to have a higher mean percentage of BSA (18.5%) than Caucasians (11%; p = 0.067), as well as higher target lesion severity (5.55 vs. 4.84; p = 0.077). Patients with psoriatic nail disease (180/221, 81%) had significantly greater number of involved distal interphalangeal (DIP) joints (p = 0.004). There were no other significant associations of skin pattern or regional involvement with PsA.
  
  
  CONCLUSIONS
  Patients with active PsA have generally mild skin disease, and baseline relationships between psoriasis and PsA tend to be weak except for nail involvement and DIP joint activity.
authors.affiliation: Medical College of Wisconsin, Milwaukee, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Cohen
authors.forename: D J
authors.initials: DJ
authors.lastname: Reda
authors.forename: D O
authors.initials: DO
authors.lastname: Clegg
mesh_terms: D001168:Arthritis / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology; D015535:Arthritis, Psoriatic / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology; D003710:Demography; D018450:Disease Progression; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology*