Pattern of Joint Involvement and Other Disease Characteristics in 634 Patients with Arthritis of Less Than 16 Weeks’ Duration

OBJECTIVE: To investigate the distribution of joint involvement in a cohort of patients with very recent onset arthritis and describe the disease characteristics in these patients. METHODS: A very early arthritis clinic (NOR-VEAC) was established as a multicenter study. General practitioners were asked to refer patients presenting with at least 1 swollen joint of maximum 16 weeks' duration. Clinical and laboratory markers were examined. RESULTS: We included 634 patients during the first 3 years, with mean (25th-75th percentile) arthritis duration of 30 (11-63) days. Monoarthritis was present in 243 (38.3%) patients, 216 (34.1%) had oligoarthritis, and 175 (27.6%) polyarthritis. Patients with polyarthritis were older, had longer duration of arthritis, and were more frequently anti-cyclic citrullinated peptide antibody and rheumatoid factor-positive. Patients in all 3 joint pattern groups (mono-/oligo-/polyarthritis) reported substantial effect on physical function, pain, and fatigue and had elevated levels of acute-phase reactants. Knee or ankle arthritis was most frequent in patients with mono- and oligoarthritis, whereas small joint involvement was most frequent in patients with polyarthritis. CONCLUSION: Patients with recent-onset arthritis report a substantial influence on health status. Mono- and oligoarthritis are at least as frequent as polyarthritis. Polyarthritic patients more frequently exhibit features associated with a worse outcome.