Which of the following is an example of inflammatory joint disease?

Rheumatoid arthritis is classified as an inflammatory joint disease because it is characterized by the immune system attacking the synovial membranes that line the joints, leading to inflammation, pain, swelling, and eventual joint damage. This autoimmune nature of rheumatoid arthritis distinguishes it as a condition driven by inflammation rather than mechanical wear and tear.

In contrast, osteoarthritis primarily results from the degeneration of joint cartilage and underlying bone, often due to aging or repetitive stress, rather than an inflammatory process. Gout, while also involving inflammation due to crystal deposits (specifically uric acid), is typically classified under metabolic disorders rather than a primary inflammatory joint disease. Fibromyalgia, although it involves chronic pain and fatigue, does not primarily affect the joints and is considered a musculoskeletal pain disorder without specific joint inflammation.