Compared with patients with psoriasis alone, patients with psoriasis and arthralgia were more likely to have baseline tenosynovitis, which may be a contributing risk factor to the development of psoriatic arthritis (PsA), according to study results published in RMD Open.
Investigators of this study examined the link between baseline ultrasonography findings, used to evaluate the anatomic basis for arthralgia, and the subsequent development of PsA in patients with psoriasis.
Patient data were recruited from 7 rheumatology and dermatology clinics in Italy: 61 psoriatic patients with arthralgia, 57 patients with psoriasis alone, and 57 age-matched healthy control participants. Clinical evaluation for ultrasound abnormalities, including inflammatory and structural lesions, was conducted, and patients were followed-up for the subsequent development of PsA, of whom those with psoriasis were reassessed every 6 months. Investigators recorded demographic data for each patient, including age, sex, body mass index, smoking status, alcohol use, and comorbidities; articular and entheseal examinations were performed by a rheumatologist. Disease severity was scored using the Psoriasis Area Severity Index and nail involvement was scored using the Nail Psoriasis Severity Index. Each patient also completed a Visual Analog Scale and a Health Assessment Questionnaire to assess musculoskeletal pain and physical function, respectively.
The only significant ultrasonographic feature that differed between patients with psoriasis with arthralgia vs patients with psoriasis alone was evidence of tenosynovitis (29.5% vs 5.3%; P <.001). Synovitis and enthesitis also occurred more frequently in patients with arthralgia compared with psoriasis alone (34.4% vs 26.3% and 27.9% vs 17.5%, respectively); however, there was no significant difference between the 2 groups. In the prospective analysis, 5 patients with psoriasis with arthralgia and 1 patient with psoriasis alone developed PsA. The incidence rate of developing PsA was significantly greater in the psoriasis with arthralgia group compared with the psoriasis group (109.2 vs 13.4 per 1000 person-years; P =.03). Development of PsA was associated with certain baseline characteristics including a significantly higher Visual Analog Scale pain score (5.92±2.01 vs 2.63±2.35; P =.004), Health Assessment Questionnaire score (0.44±0.22 vs 0.26±0.38; P =.03), tender joint count (6.8±10.87 vs 1.74±3.16; P =.03), and active enthesitis on ultrasound (0.67±0.52 vs 0.27±0.55; P =.03).
Study limitations included the small sample size and relatively short follow-up period. Future studies should replicate these findings in a larger cohort to construct a predictive model for the development of PsA.
Psoriatic patients with arthralgia had a significantly higher incidence of developing PsA and nonspecific musculoskeletal symptoms were a contributing risk factor. Since only tenosynovitis was associated with baseline psoriasis with arthralgia, the investigators suggested that tenosynovitis may be an important contributor to musculoskeletal symptoms in patients with psoriasis.
Zabotti A, McGonagle DG, Giovannini I, et al. Transition phase towards psoriatic arthritis: clinical and ultrasonographic characterization of psoriatic arthralgia. RMD Open. 2019;5(2):e001067.