title: Is there subclinical enthesitis in early psoriatic arthritis? A clinical comparison with power doppler ultrasound.
abstract: OBJECTIVE
  Enthesitis is a recognized feature of spondylarthritides (SpA), including psoriatic arthritis (PsA). Previously, ultrasound imaging has highlighted the presence of subclinical enthesitis in established SpA, but there are little data on ultrasound findings in early PsA. The aim of our study was to compare ultrasound and clinical examination (CE) for the detection of entheseal abnormalities in an early PsA cohort.
  
  
  METHODS
  Forty-two patients with new-onset PsA and 10 control subjects underwent CE of entheses for tenderness and swelling, as well as gray-scale (GS) and power Doppler (PD) ultrasound of a standard set of entheses. Bilateral elbow lateral epicondyles, Achilles tendons, and plantar fascia were assessed by both CE and ultrasound, the latter scored using a semiquantitative (SQ) scale. Inferior patellar tendons were assessed by ultrasound alone. A GS SQ score of >1 and/or a PD score of >0 was used to describe significant ultrasound entheseal abnormality.
  
  
  RESULTS
  A total of 24 (57.1%) of 42 patients in the PsA group and 0 (0%) of 10 controls had clinical evidence of at least 1 tender enthesis. In the PsA group, for sites assessed by both CE and ultrasound, 4% (7 of 177) of nontender entheses had a GS score >1 and/or a PD score >0 compared to 24% (9 of 37) of tender entheses. CE overestimated activity in 28 (13%) of 214 of entheses. All the nontender ultrasound-abnormal entheses were in the lower extremity.
  
  
  CONCLUSIONS
  The prevalence of subclinical enthesitis in this early PsA cohort was low. CE may overestimate active enthesitis. The few subclinically inflamed entheses were in the lower extremity, where mechanical stress is likely to be more significant.
authors.affiliation: University of Leeds and NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Freeston
authors.forename: L C
authors.initials: LC
authors.lastname: Coates
authors.forename: P S
authors.initials: PS
authors.lastname: Helliwell
authors.forename: E M A
authors.initials: EM
authors.lastname: Hensor
authors.forename: R J
authors.initials: RJ
authors.lastname: Wakefield
authors.forename: P
authors.initials: P
authors.lastname: Emery
authors.forename: P G
authors.initials: PG
authors.lastname: Conaghan
mesh_terms: D000125:Achilles Tendon / Q000000981:diagnostic imaging*; D000328:Adult; D015535:Arthritis, Psoriatic / Q000000981:diagnostic imaging*; D005205:Fascia / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D025241:Spondylarthritis / Q000000981:diagnostic imaging*; D052256:Tendinopathy / Q000000981:diagnostic imaging*; D018608:Ultrasonography, Doppler