title: Juvenile psoriatic arthritis: longterm outcome and differentiation from other subtypes of juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To compare outcomes in patients with juvenile psoriatic arthritis (PsA) with those in patients with other juvenile idiopathic arthritis (JIA) subtypes, and to evaluate characteristics and genetic markers that may differentiate PsA from other subtypes of JIA.
  
  
  METHODS
  JIA patients first admitted between 1980 and 1985 were clinically examined after a median of 15 years. Health status was reassessed by the Short Form-36 Health Survey (SF-36) after a median of 23 years. Of 336 JIA patients, 31 (9%) had PsA.
  
  
  RESULTS
  Predictors of PsA were psoriasis in the patient (OR 12.06, p = 0.004) or first-degree relative (OR 30.86, p < 0.001), dactylitis (OR 10.97, p < 0.001), and ankle/toe arthritis (OR 3.04, p = 0.038) within the first 6 months. HLA-DRB1*11/12 status (OR 2.69, p = 0.040) and onset after age 6 years (OR 4.41, p = 0.004) differentiated PsA from either oligoarthritis or polyarthritis. After 15 years, PsA patients had poorer physical health than healthy population controls (p = 0.001). After 23 years, the SF-36 physical scores were poorer in PsA patients than in those with either oligoarthritis or polyarthritis (p < 0.045). The need for disease-modifying antirheumatic drugs and/or anti-tumor necrosis factor agents was present in 33% of PsA versus 8% in oligoarthritis and 13% in either oligoarthritis or polyarthritis patients (p < 0.001 and p = 0.002, respectively).
  
  
  CONCLUSIONS
  In addition to a history of psoriasis, dactylitis, ankle or toe arthritis, and DRB1*11/12 in children with JIA indicate the likelihood of PsA, a subtype associated with unfavorable outcome.
authors.affiliation: Department of Rheumatology, Rikshospitalet-Oslo University Hospital, 0027 Oslo, Norway. berit.flato@rikshospitalet.no
authors.forename: Berit
authors.initials: B
authors.lastname: Flatø
authors.forename: Gunnhild
authors.initials: G
authors.lastname: Lien
authors.forename: Anna
authors.initials: A
authors.lastname: Smerdel-Ramoya
authors.forename: Odd
authors.initials: O
authors.lastname: Vinje
mesh_terms: D000293:Adolescent; D000328:Adult; D001171:Arthritis, Juvenile / Q000150:complications* / Q000175:diagnosis*; D015535:Arthritis, Psoriatic / Q000175:diagnosis*; D016022:Case-Control Studies; D002648:Child; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D016017:Odds Ratio; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553515:HLA-DRB1*12:12 antigen