Which ultrasound lesions contribute to dactylitis in psoriatic arthritis and their reliability in a clinical setting

Abstract

Objectives. To investigate the prevalence of ultrasound elementary lesions in dactylitis in psoriatic arthritis (PsA), and the reliability of scoring these lesions in a clinical setting. Methods. In 31 patients with PsA and clinical dactylitis, ultrasound assessment of the affected digit was performed using grey-scale and color Doppler mode. One examiner scanned all patients and a 2nd examiner scanned 10 patients for inter-reader reliability. The following lesions were evaluated: subcutaneous edema; soft tissue thickening; synovitis of the digital joints; tenosynovitis of the exor tendon; enthesitis at the deep exor tendon and the extensor tendon entheses; and paratenonitis of the extensor tendon. A dactylitis sum-score was calculated. Findings in clinically tender and non-tender digits were compared. Results. The most frequent lesions were soft tissue thickening (81%) and subcutaneous edema (74%) followed by synovitis (56-68%) and exor tenosynovitis (52%). Color Doppler was most frequently found subcutaneously (55%) and around the exor tendons (45%). All lesions were typically found in combinations, most commonly subcutaneous edema and synovitis (71%), subcutaneous edema and exor tenosynovitis (52%), and all three in combination (52%). Tender digits had a higher dactylitis sumscore and numerically higher prevalence of most lesions than non-tender digits. Intra-and inter-reader agreements were moderate to excellent, though lower for few components of digital enthesitis, especially hypoechogenicity. Conclusion. Dactylitis in PsA appears to encompass several pathologies, most often subcutaneous changes combined with synovitis and/or exor tenosynovitis. Reliability of scoring established ultrasound lesions of dactylitis in a clinical setting is moderate-excellent.

Imaging Findings in Patients with Immune Checkpoint Inhibitor-Induced Arthritis

“…In particular, in one patient with dactylitis ( Figure 3 ), US findings included soft tissue thickening, subcutaneous edema, flexor tenosynovitis, and synovitis, without major differences with previously-described typical PsA [ 33 ]. US findings of oligoarthritis and monoarthritis patterns showed high levels of SH and PD signals, with no particularities with respect to inflammatory arthritis.…”

The value of ultrasound-defined tenosynovitis and synovitis in the prediction of persistent arthritis

“…In addition, US studies have shown that synovitis and/or flexor TS alongside soft tissue thickening and oedema were the elementary US lesions in dactylitis [ 39 ]. In this work, we did not record the presence of clinical dactylitis in individual joints.…”

Psoriatic Dactylitis: Current Perspectives and New Insights in Ultrasonography and Magnetic Resonance Imaging

“…Another study on 12 toes from 7 PsA patients had recorded a similarly high prevalence of tenosynovitis, while joint effusion was only present in a few cases [47]. A recent US study involving 31 PsA patients (17 toes and 12 fingers) showed a high prevalence of soft tissue thickening (81%) and subcutaneous edema (74%) [48]. GS synovitis and GS flexor tenosynovitis were present in 56-68% and 52% of patients, respectively.…”

“…However, it does not include small digital entheses. Signs of enthesitis, though common in dactylitis, present less frequently than other lesions [48]. The reliability of scoring enthesitis of larger entheses has been established in spondyloarthritis [55], but this is not validated for the small digital entheses and needs further exploration.…”