What is the appropriate workup for a patient presenting with right arm pain in primary care, considering potential musculoskeletal or cardiovascular causes?

Workup for Right Arm Pain in Primary Care

Start with plain radiographs of the affected arm region, followed by a structured clinical assessment focusing on pain chronology, distribution pattern, neurological symptoms, and psychosocial factors—reserving advanced imaging (MRI or ultrasound) for cases with suspected soft tissue pathology, nerve compression, or when initial evaluation is inconclusive. 1

Initial Imaging

• Obtain plain radiographs first as the initial imaging study for chronic arm pain, which can identify fractures, heterotopic ossification, soft tissue calcification, osteoarthritis, or osteochondral lesions 1
• Radiographs are rated as "usually appropriate" by the American College of Radiology for chronic upper extremity pain and should precede any advanced imaging 1
• Compare with the contralateral asymptomatic side when findings are equivocal 1

Focused Clinical History

Obtain specific details about:

• Pain chronology and frequency: Higher baseline pain frequency strongly predicts persistent symptoms (OR 2.5) and guides urgency of intervention 2
• Distribution pattern: Determine if pain is localized (elbow, shoulder, wrist) versus diffuse, and whether it radiates—this localizes pathology to specific anatomical structures 3, 4
• Neurological symptoms: Assess for paresthesias, numbness, or tingling to identify nerve root, brachial plexus, or peripheral nerve involvement 3
• Occupational and recreational activities: Epicondylalgia ("tennis elbow" or "golfer's elbow") affects 1-3% of the population and has both occupational and recreational causes 1
• Chronic pain at other body sites: This is a strong predictor of persistent arm pain (ORs 1.6-2.4) and suggests central sensitization 2

Physical Examination Priorities

• Distinguish articular from non-articular pain through palpation, range of motion testing, and assessment of joint versus soft tissue tenderness 4
• Assess for inflammatory versus mechanical patterns: Look for warmth, swelling, and morning stiffness (inflammatory) versus pain with use (mechanical) 4
• Perform neurological examination: Test sensory distribution, motor strength in specific muscle groups, and reflexes to localize nerve pathology 3
• Evaluate shoulder range of motion and rotator cuff function: Breast cancer survivors and post-surgical patients may develop adhesive capsulitis or rotator cuff injury 1

Psychosocial Assessment

• Screen for depression, anxiety, and somatization using validated tools, as these significantly impact pain persistence and disability 1
• Assess fear-avoidance beliefs: These predict worse outcomes and should be addressed early with patient education 1, 2
• Identify "yellow flags": Psychosocial risk factors for chronic disability include catastrophizing, passive coping strategies, and belief that pain equals harm 1
• Evaluate smoking status: Current smoking strongly predicts persistent arm pain (OR 3.3) and should trigger cessation counseling 2

Advanced Imaging Indications

MRI without contrast is appropriate when:

• Radiographs are normal but clinical suspicion remains high for soft tissue pathology (tendinopathy, ligament tears, rotator cuff injury) 1
• Neurological symptoms suggest nerve compression (cubital tunnel syndrome, cervical radiculopathy) requiring anatomical confirmation 1, 3
• Osteochondral lesions or intra-articular bodies are suspected but not clearly visualized on radiographs 1

Ultrasound can be used for:

• Dynamic assessment of tendons and ligaments with the advantage of contralateral comparison 1
• Guided interventions if soft tissue pathology is confirmed 1

Red Flags Requiring Urgent Evaluation

• Male sex with elbow pain: Men have worse prognosis for persistent elbow pain (OR 1.9) and may require earlier specialist referral 2
• Unremitting pain without 7-day pain-free intervals: This pattern indicates high risk for chronic disability and warrants aggressive multimodal intervention 2
• Progressive neurological deficits: Weakness, sensory loss, or reflex changes require urgent electrodiagnostic studies and possible surgical consultation 3

Laboratory Testing

• Generally not indicated for isolated musculoskeletal arm pain unless systemic inflammatory arthritis is suspected (then order ESR, CRP, RF, anti-CCP) 1, 4
• Consider vitamin D and calcium levels only if bone health concerns exist (postmenopausal women, chronic steroid use) 1

Common Pitfalls to Avoid

• Do not order MRI before radiographs: This violates evidence-based imaging algorithms and increases costs without improving outcomes 1
• Do not attribute all arm pain to specific structural pathology: Many cases are "nonspecific" with vague, diffuse symptoms where psychological and social factors predominate over identifiable pathophysiology 5
• Do not ignore psychosocial factors when pain is severe: The instinct to focus solely on biomedical causes risks missing treatable psychological contributors that perpetuate disability 1
• Do not overlook cardiovascular causes in specific contexts: While this guideline focuses on musculoskeletal pain, arm pain can be anginal equivalent—maintain clinical vigilance for cardiac risk factors 1