Case Studies

 Case 10.2 Rheumatoid arthritis

A 37-year-old woman gradually developed painful wrists over 3 months; she consulted her doctor only when the pain and early morning stiffness stopped her from gardening. On examination, both wrists and the metacarpophalangeal joints of both hands were swollen and tender but not deformed. There were no nodules or vasculitic lesions. On investigation, she was found to have a raised C-reactive protein (CRP) level (27mg/l) (NR <10) but a normal haemoglobin and white-cell count. A latex test for rheumatoid factor was negative and antinuclear antibodies were not detected.

The clinical diagnosis was early rheumatoid arthritis and she was treated with ibuprofen. Despite some initial symptomatic improvement, the pain, stiffness and swelling of the hands persisted and 1 month later both knees became similarly affected. She was referred to a rheumatologist.

Six months after initial presentation, she developed two subcutaneous nodules on the left elbow; these were small, painless, firm and immobile but not tender. A test for rheumatoid factor was now positive (titre 1/64). 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 and, had she had a biopsy, pannus would have been demonstrable histologically.

This woman now had definite X-ray evidence of rheumatoid arthritis and, in view of the continuing arthropathy, her treatment was changed to weekly low-dose methotrexate. This has controlled the arthritis for several years and no further erosions have developed.