Does a patient with acute ankle swelling of 2 days duration, no calf tenderness, and a Wells' criteria score of 1 require emergency department (ED) evaluation?

Acute Ankle Swelling with Wells Score of 1: ED Referral Not Required

A patient with acute ankle swelling of 2 days duration, no calf tenderness, and a Wells score of 1 does not require emergency department evaluation and can be safely managed in the outpatient setting with appropriate follow-up. 1

Risk Stratification for DVT

Your patient has a low probability for deep vein thrombosis based on the Wells criteria:

• A Wells score of 1 places this patient in the low-risk category (score <2), which correlates with approximately 7-8% prevalence of proximal DVT 2
• The absence of calf tenderness is particularly reassuring, as "no leg swelling" is significantly negatively correlated with DVT diagnosis 3
• A Wells score <1 can reliably rule out DVT with 100% sensitivity and 100% negative predictive value in trauma patients, and your score of 1 remains in the low-risk threshold 4

Appropriate Outpatient Management Pathway

For this low-risk presentation, follow this algorithm:

1. Obtain D-dimer testing if clinically indicated for DVT concern - a negative D-dimer (<500 μg/L) in a low-risk patient effectively excludes DVT and no further testing is needed 2

2. Assess for traumatic injury using clinical examination:

   • Determine if the patient can bear weight immediately after injury and ambulate 4 steps 1
   • Check for point tenderness over the posterior edge or inferior tip of the medial/lateral malleolus, talus, or calcaneus 1
   • If Ottawa Ankle Rules are negative (able to walk, no point tenderness), radiographs are not indicated 5, 1

3. Consider alternative diagnoses for unilateral ankle swelling:

   • Localized infection (cellulitis)
   • Traumatic soft tissue injury
   • Medication-related edema 1

When to Image

Radiographs are only indicated if:

• Unable to bear weight immediately after injury, OR
• Point tenderness over specific bony landmarks (malleoli, talus, calcaneus), OR
• Unable to ambulate 4 steps 5, 1

The Ottawa Ankle Rules have 92-100% sensitivity for fractures, making them highly reliable for ruling out the need for imaging 1

Critical Pitfalls to Avoid

• Do not overlook medication-related edema as a cause of ankle swelling - review the patient's medication list 1
• Do not order unnecessary imaging when Ottawa Ankle Rules are negative - this leads to false-positive findings and patient harm 1
• In diabetic patients with peripheral neuropathy, maintain higher suspicion as fractures may be present despite minimal pain or ability to walk 6, 1
• Do not use diuretics unless systemic fluid overload is identified 1

Follow-Up Strategy

Arrange outpatient follow-up within 3-5 days to:

• Reassess clinical progression
• Ensure D-dimer results are reviewed if obtained
• Re-evaluate if symptoms worsen or new concerning features develop (increasing pain, warmth, erythema, inability to bear weight) 2

ED referral would only be warranted if the patient develops high-risk features: hemodynamic instability, severe pain disproportionate to examination, signs of compartment syndrome, or inability to arrange timely outpatient D-dimer testing in a patient where DVT remains a concern 5