Patient Data Exhibits Click to indicate which findings are indicative of rheumatoid arthritis or are not applicable to that disease. Each row must have only one response option selected.

Rationale: • Joint swelling: In rheumatoid arthritis (RA), joint swelling results from synovial membrane inflammation, leading to increased fluid and thickening within the joint capsule. Swollen joints are tender and may feel warm to the touch. Swelling is a key clinical sign of active disease and contributes to joint deformity over time if untreated. • Pain increases with motion: Pain with movement is a typical feature of RA because inflamed joints are sensitive to mechanical stress. As the joint capsule becomes swollen and irritated, using the joint increases the discomfort. This distinguishes RA from other conditions where pain might be more pronounced at rest. • Morning stiffness quickly resolves: In RA, morning stiffness usually lasts longer than 30 minutes and often persists for several hours. If stiffness resolves quickly (within minutes), it is more typical of osteoarthritis or mechanical joint issues rather than inflammatory arthritis like RA. Thus, quick resolution is not applicable to RA. • Fatigue and fever: RA is a systemic inflammatory disease, meaning it can affect the whole body, not just the joints. Cytokine release during active disease often causes generalized symptoms such as fatigue, low-grade fever, malaise, and weight loss, highlighting the autoimmune nature of the condition. • Small joints of the hand: RA typically affects the small joints first — especially the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. This early involvement of the fingers and hands helps differentiate RA from osteoarthritis, which often targets larger, weight-bearing joints initially. • Symmetrical involvement: A hallmark of RA is symmetrical joint involvement, meaning that the same joints on both sides of the body are affected. Symmetry helps distinguish RA from other types of arthritis such as gout or septic arthritis, which tend to be asymmetrical and localized. • Heberden nodes: Heberden nodes are bony swellings at the distal interphalangeal (DIP) joints, characteristic of osteoarthritis, not RA. RA rarely affects DIP joints and does not form hard bony nodules at the joint surface. Therefore, Heberden nodes are considered not applicable to RA findings.