AB1134 ULTRASOUND FINDINGS IN HAND JOINTS INVOLVEMENT: A COMPARATIVE STUDY BETWEEN PSORIATIC AND RHEUMATOID ARTHRITIS

Abstract

Background:Psoriasis is a common skin disease that is associated with multiple conditions. The most prevalent coexisting condition is psoriatic arthritis (PsA) which develops in up to 30% of patients with psoriasis and characterized by diverse clinical features often resulting in delayed diagnosis and treatment. [1]Objectives:The aim of this study was to investigate the potential of ultrasound (US) in the differential diagnosis between rheumatoid arthritis (RA) and PsA at the level of small joints of the hand and wrist.Methods:Fifteen patients with PsA of the hands and wrists and 20 age and sex-matched RA patients were examined with musculoskeletal US. Radiocarpal, midcarpal, distal radioulnar, metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints and flexor and extensor tendons (in wrist and hand) were examined bilaterally. Synovitis, erosions and tenosynovitis were scored according to semiquantitative method.[2]Results:Among 510 and 680 joints examined in PsA and RA respectively, certain US features such as synovitis and erosions at the DIP were exclusively detected in PsA (p<0.001). Synovitis was frequently present at the radioulnar joints in RA in comparison to PsA patients (52.5% vs 26.7% respectively, p=0.029). Joint effusion was frequently detected at radiocarpal and midcarpal joints in RA in comparison to PsA (p=0.047, 0.039 respectively). Effusion at the 3rdPIP joints was more significantly present in PSA than RA (p=0.037),while erosions were significantly detected at radiocarpal joints in RA in comparison to PsA patients (45%vs 20%respectively,p=0.029).Tenosynovitis was significantly detected at the extensor tendons in RA and at the flexor tendons in PsA patients (p=0.021, 0.022 respectively).Conclusion:There are significant differences in the US findings of the hand and wrist that can help to distinguish between RA and PsA