A nurse is assessing a client diagnosed with rheumatoid arthritis who reports morning stiffness lasting for more than an hour. Which characteristic best distinguishes rheumatoid arthritis from osteoarthritis?

Rationale: A. While both rheumatoid arthritis (RA) and osteoarthritis (OA) can cause joint swelling, RA typically involves symmetric joint inflammation affecting multiple joints, particularly the small joints of the hands and feet, whereas OA is more localized and asymmetric. Thus, localized swelling alone does not distinguish RA from OA. B. A hallmark of RA is prolonged morning stiffness lasting more than 30–60 minutes, which eases with movement and activity. In contrast, OA typically causes brief morning stiffness (<30 minutes) that may worsen with activity. The duration of morning stiffness and its improvement with activity is a key distinguishing characteristic of RA. C. While RA can cause pain at rest due to inflammation, this feature alone is not specific enough to distinguish RA from OA. OA pain is often activity-related but can also occur at rest in advanced stages. D. RA frequently leads to joint deformities, such as ulnar deviation, swan-neck, and boutonniere deformities, especially in the small joints. OA can also cause deformities, but these are usually due to bony overgrowths (Heberden’s and Bouchard’s nodes). Therefore, stating no deformities occur is inaccurate for RA.