Characteristics of patients presenting with concomitant carpal tunnel syndrome at the initial diagnosis with rheumatoid arthritis

Objective To investigate the clinical characteristics of patients who presented with concomitant carpal tunnel syndrome (CTS) at the initial diagnosis with rheumatoid arthritis (RA).Methods We analyzed patients with newly diagnosed RA at a single institution between 2012 and 2021. Patient demographic and laboratory data, the 2010 ACR/EULAR classification criteria, and the duration from the initial visit to RA diagnosis were compared between RA patients with concomitant CTS (RA with CTS group) and those without CTS (RA without CTS group).Results The study included 235 patients (157 females), of which 11 patients (4.7%) presented with CTS at the initial diagnosis with RA. In the RA with CTS group, the age was significantly higher (P = .033), all patients were female, and anti-cyclic citrullinated peptide antibody (ACPA) was negative, and the duration to RA diagnosis was longer than in the RA without CTS group. Among all RA with CTS patients, ultrasonography showed power Doppler signal-positive tenosynovitis in the carpal tunnel, which is not usually detected in idiopathic CTS.Conclusions Patients with concomitant CTS at the initial diagnosis with RA were characterized by old age, female sex, and negative ACPA. Patients with symptoms of CTS should undergo ultrasonography for early diagnosis of RA.