Rheumatoid arthritis (RA) classically causes a symmetrical, small joint polyarthritis which left untreated can lead to joint destruction and deformity. NICE recommends that any adult with suspected persistent synovitis of undetermined cause should be referred for a specialist opinion. Patients should be referred urgently (even with a normal acute-phase response, negative anti-CCP antibodies or rheumatoid factor) if any of the following apply: the small joints of the hands or feet are affected; > 1 joint is affected; there has been a delay of ≥ 3 months between onset of symptoms and seeking medical advice.