Background and aims Sarcoidosis is known as a Th1-mediated disease which can mimic many primary rheumatologic diseases or sometimes co-exist with them. Clinical characteristics of sarcoid arthropathy are not well described and the studies reported in the literature so far are mostly based on the data from referrals. The aim of this study was to evaluate the incidence and clinical characteristics of sarcoid arthropathy.

Methods All our patients were prospective evaluated in our single Rheumatology outpatient centre from 2011 to 2015. 114 patients with sarcoidosis were included in the study.

Results The mean patient age was 48.1 years and the mean disease duration was 40.5 months.Sarcoid arthritis was observed in 71 (62.3%),and arthralgia in 106 (92.9%) patients.Out of the 71 patients with arthritis, 61 (85.9%) had involvement of ankle, 7 (9.8%) knee, 2 (2.8%) wrist, MCP and PIP joints, and one (1.4%) had shoulder periarthritis. Oligoarthritis (two to four joints) was the most common pattern followed by monoarthritis and polyarthritis. When the correlation between clinical findings was considered, erythema nodosum and arthritis and female gender were found to be correlated (p=0.03, p=0.001, respectively). Again in patients with arthritis, even higher levels of CRP/ESR as well as ANA and RF positivity were observed (p=0.03, p=0.01, p=0.01 and p=0.02, respectively). Eleven patients had another rheumatic pathology concurrent with sarcoidosis.

Conclusions Inflammatory arthritis occurs in a majority of patients with sarcoidosis. Acute arthritis with bilateral ankle involvement is the most common pattern of sarcoid arthropathy. Sarcoidosis can mimic many primary rheumatic diseases and/or may coexist with them.