title: Distal extremity swelling with pitting edema in psoriatic arthritis: a case-control study.
abstract: OBJECTIVE
  To evaluate the frequency and the clinical characteristics of distal extremity swelling with pitting edema in patients with psoriatic arthritis (PsA).
  
  
  METHODS
  This was a case-control study of consecutive outpatients with PsA (old and new diagnosis) observed over a 3-month period in three secondary referral centers in Italy. As controls we used the two consecutive rheumatic outpatients, excluding those with spondylarthropathies, observed after a PsA patient. The demographic and clinical features were assessed by clinical examination and review of the medical records.
  
  
  RESULTS
  A total of 183 patients with PsA and 366 controls were evaluated. Distal extremity swelling with pitting edema was recorded in 39/183 (21%) PsA patients and in 18/366 (4.9%) controls (p < 0.0001). In 8/39 (20%) patients this feature presented as a first, isolated manifestation of PsA, and in 8 others it was associated with other features of PsA at diagnosis. The upper and lower extremities were affected, predominantly asymmetrically, in 40% and 60% of the cases respectively. In patients with pitting edema compared to those without this feature, the frequency of Achilles enthesitis and plantar fasciitis, calculated together, was higher (p < 0.05) and the duration of arthritis was significantly lower (p = 0.02). In 7 patients the clinical evidence of a predominant involvement of tenosynovial structures was confirmed by MRI.
  
  
  CONCLUSIONS
  Upper or lower distal extremity swelling with pitting edema due to tenosynovitis, usually unilateral, is a common feature in PsA patients and may represent the first, isolated manifestation of the disease.
authors.affiliation: Unità Reumatologica, II Divisione di Medicina, Ospedale di Prato, Piazza Ospedale 1, 59100 Prato, Italy. fcantini@conmet.it
authors.forename: F
authors.initials: F
authors.lastname: Cantini
authors.forename: C
authors.initials: C
authors.lastname: Salvarani
authors.forename: I
authors.initials: I
authors.lastname: Olivieri
authors.forename: L
authors.initials: L
authors.lastname: Macchioni
authors.forename: L
authors.initials: L
authors.lastname: Niccoli
authors.forename: A
authors.initials: A
authors.lastname: Padula
authors.forename: C
authors.initials: C
authors.lastname: Falcone
authors.forename: L
authors.initials: L
authors.lastname: Boiardi
authors.forename: A
authors.initials: A
authors.lastname: Bozza
authors.forename: L
authors.initials: L
authors.lastname: Barozzi
authors.forename: P
authors.initials: P
authors.lastname: Pavlica
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015535:Arthritis, Psoriatic / Q000175:diagnosis*; D016022:Case-Control Studies; D004487:Edema / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013717:Tenosynovitis / Q000175:diagnosis*