1. Pattern of Joint Pain and Involvement

Feature Rheumatoid Arthritis (RA) Osteoarthritis (OA)
Onset Insidious; over weeks to months Gradual; developing over years
Symmetry Symmetrical polyarthritis Often asymmetrical, but can be symmetrical in hands
Joints Affected Small joints of hands (MCP, PIP), wrists, feet, knees, ankles; spares DIP Large weight-bearing joints (knees, hips); hands (DIP, PIP, 1st CMC); spine; spares wrists, elbows, ankles, shoulders
Joint Distribution Multiple joints, especially small joints of hands, feet Fewer joints, mainly large joints or specific hand joints^1^ 1,^2^ 2

2. Stiffness

Feature Rheumatoid Arthritis (RA) Osteoarthritis (OA)
Morning Stiffness >1 hour (often several hours), lessens with activity <30 minutes, improves quickly with movement, recurs after rest ("gel phenomenon")
Stiffness After Inactivity Yes, marked Yes, but typically less pronounced

3. Pain Characteristics

Feature Rheumatoid Arthritis (RA) Osteoarthritis (OA)
Timing Worse in morning and after inactivity; improves with use Worsens with activity and as day progresses; relieved by rest
Pain Quality Aching, sometimes sharp during flares, with swelling Dull ache, worsens with weight-bearing/use

4. Systemic Features

Feature Rheumatoid Arthritis (RA) Osteoarthritis (OA)
Fever, Malaise, Weight Loss, Fatigue Common, especially at onset or during flares Uncommon
Other May have extra-articular manifestations (nodules, anaemia, lung, cardiac) Not typical; generally local disease

5. Physical Examination and Deformities

RA:

OA: