The prevalence of synovitis and tenosynovitis in the small joints of the hands using ultrasonography in patients with chronic plaque psoriasis but undiagnosed psoriatic arthritis

Abstract

Introduction: Psoriatic arthritis (PsA) is a chronic systemic inflammatory disorder seen in psoriasis patients characterized by chronic inflammation of peripheral joints and axial skeleton. In most cases of PsA, patients have the preceding onset of cutaneous manifestations prior to developing joint symptoms. As this is a deforming arthropathy, a delay in the diagnosis is associated with adverse long-term outcomes. PsA significantly impairs quality of life and physical function. We aim to study the prevalence of early synovitis with tenosynovitis in with chronic plaque psoriasis but undiagnosed psoriatic arthritis using ultrasonography. Method: This is a cross-sectional study done in Hospital Serdang on consecutive chronic plaque psoriasis patients in the outpatient clinic. All patients will be assessed clinically and subsequently undergo ultrasonography of the small joints of the hands to detect synovitis and tenosynovitis. Results: Fifty-nine patients were recruited, comprising of 25 males and 34 females. The median disease duration of psoriasis was 7 years (14 to 74 years). Using a 6-item screening questionnaire, 29 patients (49%) were considered to have probable arthritis. The dermatologist clinically detected 8 patients with synovitis and the rheumatologist detected 10 patients with synovitis. The inter-observer variability between the dermatologist and rheumatologist was not significant (p>0.1). Eight patients were confirmed to have synovitis and 7 with tenosynovitis using the ultrasound. The correlation of synovitis and tenosynovitis with disease severity was not significant (p=0.25). Conclusion: The prevalence of synovitis and tenosynovitis of hand joints in patients with chronic plaque psoriasis without a prior history of arthropathy was 22%. We advocate routine assessment of joints to be done by dermatologists and refer for further ultrasonography evaluation as clinically indicated.