A 37-year-old woman gradually developed painful wrists over 3 months; she consulted a doctor only when the pain and early morning stiffness stopped her from gardening. Examinations: Both wrists and the metacarpophalangeal joints of both hands were swollen and tender but not deformed. There were no nodules or vasculitic lesions. Investigations: She was found to have a raised C-reactive protein (CRP) level (27mg/l) (NR <10) but a normal hemoglobin and white cell count. A latex test for rheumatoid factor was negative and antinuclear antibodies were not detected.
Six months after the initial presentation: She developed two subcutaneous nodules on the left elbow; these were small, painless, firm and immobile but not tender. X-rays of the hands showed bony erosions in the metacarpal heads. She still had a raised CRP (43mg/l) but normal serum complement (C3 and C4) levels. What would be the…
