Acute Polyarticular Joint Pain Diagnosis and Management

Critical Initial Assessment

The American College of Radiology recommends ruling out septic arthritis, which is an orthopedic emergency requiring immediate intervention, in patients with acute severe pain in multiple joints, particularly if there are fever and systemic symptoms, inability to bear weight or move the joint, or recent bacteremia or infection elsewhere 1
Fever and systemic symptoms strongly suggest septic arthritis, which requires urgent evaluation 1
Inability to bear weight or move the joint is a red flag requiring urgent evaluation 1
Recent bacteremia or infection elsewhere increases the suspicion of septic arthritis 1

The American College of Radiology suggests that plain radiographs (AP and lateral views) of the affected knee should be obtained as the initial imaging study to assess for fractures, joint effusion, or degenerative changes 3, 2
Urgent joint aspiration with synovial fluid analysis is recommended if significant effusion is present and infection is suspected 1
Inflammatory markers such as ESR and CRP should be measured, with CRP >2.0 mg/dL increasing the probability of septic arthritis 1
Blood cultures should be obtained if fever is present 1

If septic arthritis is suspected or cannot be ruled out, immediate orthopedic consultation, urgent joint aspiration, empiric IV antibiotics after cultures are obtained, and hospital admission are recommended 1
If crystal arthropathy is most likely after excluding infection, conservative management with NSAIDs, rest, and ice to affected joints, and close follow-up within 24-48 hours to reassess response are recommended 1, 2

If symptoms persist beyond 5-7 days despite treatment, or if mechanical symptoms or instability develop, MRI may be considered to evaluate for soft tissue pathology, occult fractures, or internal derangement 2, 1, 3