Ultrasonography Enthesitis and Synovitis Screening in Psoriatic Patients: A Case Control Study.

Background: The clinical screening of enthesitis and synovitis in patients with psoriasis lacks specificity and sensitivity during the preclinical phase.

Aims: to assess US subclinical synovitis and enthesitis in psoriatic patients compared with healthy controls.

Methods: A cross-sectional study on 40 psoriatic patients and 40 healthy sex- and age-matched controls. US examination of 18 joints was performed along with 22 entheseal sites on the upper and lower limbs. US subscores were established according to the US abnormalities: inflammatory score (tendon thickening, hypoechogenicity, bursitis, Doppler signal), damage score (calcification, enthesophytes, bone erosion) and total score (the sum of inflammatory and damage scores).

Results: US synovitis were more frequent in psoriatic patients (0.68%) than in controls (0.29%), but the difference was not significant. Patients with psoriasis had more US enthesitis (92,5%) compared to controls (40%)(p<0.001). The total number of enthesitis was higher in the psoriatic group (20.90%) compared to controls (4,78%)(p<0.001). There were more US abnormalities in the psoriatic group compared to controls for calcaneal tendon enthesis(p<0.001), distal patellar tendon enthesis(p<0.001) and deep flexor tendons of the finger enthesis(p<0.001). Compared to controls, psoriatic patients had a significantly higher inflammatory score (Mean±SD) (2.85±3.34 versus 0.58±1.17), damage score (3±2.57 versus 0.60±1.41), and total score (5.85±5.20 versus 1.18±2.07) (p < 0.001 each). Patients with scalp psoriasis had more US enthesitis (p=0.020).

Conclusion: Our results indicate that US enthesitis and synovitis are more frequent in patients with psoriasis. Prospective studies with larger sample size are needed to define the contribution of US in predicting the clinical onset of PsA.