Musculoskeletal Ultrasound Increases Specificity for Diagnosing Psoriatic Arthritis

According to a study published in Rheumatology, musculoskeletal ultrasound (MSUS) used by dermatologists as a screening instrument for psoriatic arthritis (PsA) leads to a more precise diagnosis and less referrals to rheumatologists.

Researchers evaluated the value of MSUS use by dermatologists previously trained on a novel handheld, chip-based ultrasound device (HHUD) to screen for early PsA in a prospective double-blind study. A total of 12 dermatologists participated in the study. Between October 1, 2020, and May 26, 2021, a total of 140 patients with arthralgia were screened based on medical history, clinical examination, and the GEPARD questionnaire paired with an MSUS examination of up to 3 painful joints and then referred to rheumatologists who determined the final diagnosis. MSUS screening effect was assessed according to the sensitivity and specificity before and after application.

PsA was diagnosed in 13.6% of the participants. Before applying MSUS, dermatologists’ screening sensitivity was 88.2% and specificity was 54.4%. After applying MSUS, the sensitivity was 70.6% and specificity was 90.4%. PsA was no longer suspected in 45 cases.

“This study was able to demonstrate that PsA screening using MSUS by previously trained dermatologists can lead to more precise PsA detection and potentially decreased rheumatologist referral rates,” concluded the study authors.

Reference
Grobelski J, Wilsmann-Theis D, Karakostas P, Behning C, Brossart P, Schäfer VS. Prospective double-blind study on the value of musculoskeletal ultrasound by dermatologists as a screening instrument for psoriatic arthritis. Rheumatology (Oxford). Published online ahead of print December 20, 2022. doi:10.1093/rheumatology/keac702