From the Guidelines
The initial workup for a patient presenting with polyarthralgia affecting the shoulders, elbows, buttocks, and knees should include a comprehensive history, physical examination, and targeted laboratory tests, as outlined in the most recent guidelines 1. The patient's history should focus on symptom onset, duration, pattern, morning stiffness, associated symptoms, family history of rheumatic diseases, and recent infections. The physical examination should assess all joints for swelling, tenderness, warmth, range of motion, and any extra-articular manifestations. Laboratory tests should include:
- Complete blood count
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Rheumatoid factor (RF)
- Anti-cyclic citrullinated peptide antibodies (anti-CCP)
- Antinuclear antibodies (ANAs)
- Uric acid level
- Metabolic panel Consider testing for infectious causes like Lyme disease or viral infections if clinically indicated. Plain radiographs of the affected joints can help identify structural changes or erosions. Synovial fluid analysis may be necessary if joint effusion is present to rule out infection, crystal arthropathy, or inflammatory arthritis. This comprehensive approach helps differentiate between inflammatory arthritis (like rheumatoid arthritis), spondyloarthropathies, crystal-induced arthritis, osteoarthritis, or systemic conditions with joint manifestations, guiding appropriate treatment strategies, as recommended by the European League Against Rheumatism (EULAR) 1. Initial evaluation should also include joint count, analysis of synovial fluid whenever possible, X-rays and ultrasound (US) of affected joints, as suggested by the most recent study 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Initial Workup for Polyarthralgia
The initial workup for a patient presenting with polyarthralgia in shoulders, elbows, buttock, and knee involves a combination of laboratory tests, physical examination, and medical history.
- The patient's symptoms, including inflammation, location of pain, duration of symptoms, and presence of systemic symptoms, should be thoroughly evaluated 2.
- A systematic approach to the physical examination should be used to assess for a pattern of joint involvement and presence of synovitis 2.
- Laboratory tests, such as rheumatoid factor (RF) and cyclic citrullinated peptide antibody tests, can be helpful in diagnosing rheumatoid arthritis (RA) 3, 4, 2.
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) tests can also be used to evaluate disease activity and severity in conditions such as polymyalgia rheumatica (PMR) 5 and RA 3, 4, 6.
- It is essential to note that normal ESR, CRP, and RF are seen in a substantial proportion of patients with RA at presentation, with 35%-45% of patients having normal values 6.
Laboratory Tests
- RF, anti-CCP antibody, CRP, and ESR tests can be used to diagnose RA, with anti-CCP antibody being more specific than the other parameters 3, 4.
- The combination of RF and anti-CCP antibody tests can be beneficial in confirming a diagnosis of RA 3.
- ESR and CRP tests can be used to evaluate disease activity and severity in PMR, with ESR being a superior predictor of relapse than CRP 5.
Imaging Studies
- Conventional radiography remains the standard for the initial imaging evaluation of RA 2.
- Magnetic resonance imaging (MRI) can be highly sensitive in identifying erosive bony changes and inflammation, but is not typically used as the initial imaging modality 2.
- Point-of-care musculoskeletal ultrasonography can be a useful tool to detect findings that support a diagnosis of inflammatory arthritis 2.