What is defined as an autoimmune disease characterized by symmetrical polyarthritis lasting at least 6 weeks?

• A. Osteoarthritis
• B. Gout
• C. Psoriatic arthritis
• D. Rheumatoid Arthritis

Answer: (D)

Rheumatoid arthritis is an autoimmune inflammatory arthritis defined by chronic synovitis with symmetrical joint involvement, typically lasting more than six weeks. This pattern—many joints on both sides, especially the small joints of the hands and feet—along with persistent inflammation (often with morning stiffness longer than 30 minutes) points to RA. Autoimmune features are common, with antibodies such as rheumatoid factor or anti-CCP frequently present, and unchecked disease leads to joint erosions from pannus formation.

Osteoarthritis is degenerative and usually asymmetric, focused on weight‑bearing joints. Gout presents as acute, often monoarticular arthritis from urate crystals. Psoriatic arthritis can be inflammatory and may be symmetric but is associated with psoriasis and other distinctive signs (like dactylitis or enthesitis). The combination of autoimmune etiology, symmetric polyarthritis, and a duration of at least six weeks makes rheumatoid arthritis the best fit.