What are the initial orders for a patient presenting to the Emergency Department (ED) with suspected cellulitis of the leg or Deep Vein Thrombosis (DVT)?

Initial Orders for Suspected Cellulitis of Leg or DVT in the Emergency Department

For patients presenting to the Emergency Department with suspected cellulitis of the leg or DVT, initial orders should include parenteral anticoagulation for patients with moderate to high suspicion of DVT while diagnostic testing is performed, along with appropriate antibiotics for suspected cellulitis. 1

Diagnostic Workup

Initial Assessment

• Complete blood count with differential
• Basic metabolic panel
• C-reactive protein and/or ESR (inflammatory markers)
• Blood cultures (if systemic symptoms present)
• Duplex ultrasound of the affected leg

Imaging

• Compression ultrasound (CUS) is the first-line imaging test for suspected DVT 1
  • For high clinical suspicion: Proximal CUS or whole-leg US
  • For moderate clinical suspicion: Highly sensitive D-dimer or proximal CUS
  • For low clinical suspicion: No immediate anticoagulation if test results expected within 24 hours

Laboratory Tests

• D-dimer testing:
  • Highly sensitive D-dimer as initial test in moderate-risk patients
  • Negative D-dimer in low/moderate risk patients can rule out DVT without further imaging 1
  • Note: D-dimer may be elevated in cellulitis due to inflammation

Treatment Algorithm

If Suspecting DVT:

1. Assess clinical probability of DVT

2. For moderate to high clinical suspicion:

   • Start parenteral anticoagulation while awaiting test results 1
   • Options include LMWH, fondaparinux, IV unfractionated heparin, or SC unfractionated heparin
   • LMWH or fondaparinux preferred over IV UFH (Grade 2C) and over SC UFH (Grade 2B for LMWH) 1

3. If DVT confirmed:

   • Continue anticoagulation
   • Begin VKA (warfarin) on same day as parenteral therapy
   • Continue parenteral anticoagulation for minimum 5 days and until INR ≥2.0 for at least 24 hours 1
   • Consider home treatment if home circumstances are adequate 1

If Suspecting Cellulitis:

1. Empiric antibiotic therapy:

   • Coverage for Streptococcus and Staphylococcus species
   • Consider MRSA coverage if risk factors present
   • IV antibiotics for severe infection or systemic symptoms
   • Oral antibiotics for mild to moderate infection

2. Supportive measures:

   • Elevation of affected limb
   • Warm compresses
   • Pain management
   • Marking the borders of erythema to monitor progression

Important Considerations

Differential Features

• Cellulitis features: Erythema with distinct margins, warmth, tenderness, possible fever, rigors, elevated WBC 2
• DVT features: Unilateral leg swelling, pain, tenderness, warmth, less likely to have distinct margins of erythema 2

Concomitant Conditions

• Recent research shows DVT occurs in approximately 12% of patients with lower leg cellulitis 3
• Consider screening for DVT in cellulitis patients, especially those with risk factors 3

Pitfalls to Avoid

1. Missing compartment syndrome - Severe cellulitis can lead to compartment syndrome requiring surgical decompression 4
2. Overlooking deep abscesses - Deep collections may mimic DVT symptoms 5
3. Failing to recognize both conditions can coexist - Inflammation from cellulitis may promote thrombosis 6

Home vs. Hospital Treatment

• For DVT: Consider outpatient treatment if:

  • Home circumstances are adequate (well-maintained living conditions, support system)
  • Patient feels well enough
  • No severe symptoms or comorbidities 1

• For cellulitis: Consider hospitalization if:

  • Systemic symptoms (high fever, hypotension)
  • Failed outpatient therapy
  • Immunocompromised status
  • Severe pain or rapid progression

By following this systematic approach to diagnosis and initial management, clinicians can effectively differentiate between and appropriately treat both cellulitis and DVT in the emergency department setting.