What are the red flags for shoulder pain?

Red Flags for Shoulder Pain

The following signs and symptoms should be screened at initial presentation to exclude serious pathology:

Musculoskeletal Red Flags

• Unexplained deformity, swelling, or skin erythema
• Significant weakness not attributable to pain (e.g. positive drop test with acute trauma suggests acute rotator cuff tear or fracture)
• Open fractures or fractures with nerve/vascular compromise
• Hot, tense joint suggesting infection, inflammation, or tumour

Malignancy

• Past history of malignancy, particularly lung cancer (7% of bony metastases occur in the proximal humerus)
• Suspected malignancy: unexplained weight loss, loss of appetite, night pain, or other constitutional symptoms

Infection / Systemic Illness

• Fevers, chills, malaise
• Raised CRP, redness, swelling, with systemic features

Neurological

• Significant unexplained sensory or motor deficits in the arm

Inflammatory Arthropathy

• History of rheumatoid arthritis, psoriatic disease, or crystal arthritis with evidence of active disease elsewhere or effusion

Referred / Non-musculoskeletal Causes

• Ischaemic cardiac pain (myocardial infarction)
• Diaphragmatic, pericardial, or mediastinal pleural irritation mimicking shoulder pain
• Pulmonary or vascular compromise (e.g. pulmonary embolism, vascular injury)

Other Considerations

• Polymyalgia rheumatica: bilateral shoulder pain and weakness, particularly in patients >50 years; must be assessed for temporal arteritis
• Acute compartment syndrome: pain disproportionate to injury following trauma or tight bandage/cast; a surgical emergency

The presence of any red flag warrants urgent investigation and/or referral to an appropriate specialist.