Which sign is classic in late-stage rheumatoid arthritis?

Which sign is classic in late-stage rheumatoid arthritis?

• A. Swan neck deformity
• B. Effusion to the knees
• C. Peripheral neuropathy
• D. Subcutaneous nodules on elbows

Answer: (A)

Chronic rheumatoid arthritis causes progressive destruction of joints and the soft tissues around them, so deformities in the hands become a clear sign as the disease advances. The swan neck deformity—where the proximal interphalangeal joint (PIP) is hyperextended while the distal interphalangeal joint (DIP) is flexed—arises from damage to the volar plate and imbalance of the finger extensor and intrinsic muscles due to ongoing inflammation. This pattern directly reflects long‑standing joint destruction and ligamentous laxity in the hand, making it a classic late‑stage finding. Other signs like knee effusion can occur but aren’t as specifically characteristic of late‑stage disease, and while subcutaneous nodules on the elbows are a feature of longstanding RA, they don’t illustrate the functional hand deformity as clearly. Peripheral neuropathy isn’t a defining late‑stage feature. So the swan neck deformity best signals late‑stage rheumatoid involvement.

Chronic rheumatoid arthritis causes progressive destruction of joints and the soft tissues around them, so deformities in the hands become a clear sign as the disease advances. The swan neck deformity—where the proximal interphalangeal joint (PIP) is hyperextended while the distal interphalangeal joint (DIP) is flexed—arises from damage to the volar plate and imbalance of the finger extensor and intrinsic muscles due to ongoing inflammation. This pattern directly reflects long‑standing joint destruction and ligamentous laxity in the hand, making it a classic late‑stage finding. Other signs like knee effusion can occur but aren’t as specifically characteristic of late‑stage disease, and while subcutaneous nodules on the elbows are a feature of longstanding RA, they don’t illustrate the functional hand deformity as clearly. Peripheral neuropathy isn’t a defining late‑stage feature. So the swan neck deformity best signals late‑stage rheumatoid involvement.