musculoskeletal and connective tissue disorders
Pain in Multiple Joints
Key Points
The differential diagnosis of polyarticular joint pain can be narrowed by considering which and how many joints are affected, whether inflammation is present, whether joint distribution is symmetric, and whether any extra-articular symptoms or signs are present. Chronic polyarthritis is most often caused by juvenile idiopathic arthritis in children and chronic polyarthralgia is most often caused by osteoarthritis and rheumatoid arthritis in adults. Acute polyarticular arthritis is most often due to infection, gout, or a flare of a systemic inflammatory disease. Arthrocentesis is mandatory in most cases of a new effusion to rule out infection, diagnose crystal-induced arthropathy, and help distinguish between an inflammatory and noninflammatory process. 