Which presentation is most characteristic of rheumatoid arthritis on exam?

• A. Symmetric swelling of small joints including MCP and PIP with possible ulnar deviation
• B. Isolated swelling of a large joint
• C. Erythema without swelling
• D. Pain only with movement

Answer: (A)

Inflammatory, symmetric involvement of small joints is the hallmark of rheumatoid arthritis on exam. The classic finding is swelling in the small joints of the hands, especially the metacarpophalangeal and proximal interphalangeal joints, often with ulnar deviation as the disease progresses. This symmetric pattern helps distinguish RA from other joint problems: swelling in a single large joint points to a focal process, erythema without swelling suggests a skin or soft-tissue issue, and pain that occurs only with movement is more typical of mechanical joint disease like osteoarthritis. Therefore, the presentation of symmetric swelling of small hand joints, including the MCPs and PIPs with possible ulnar deviation, best fits rheumatoid arthritis.