What is the recommended treatment for cellulitis of the left leg?

Treatment of Cellulitis of the Left Leg

For typical non-purulent cellulitis of the left leg, the recommended first-line treatment is an antibiotic active against streptococci, such as penicillin, amoxicillin, dicloxacillin, cephalexin (500 mg four times daily), or clindamycin for a 5-day course. 1, 2

Antibiotic Selection

• For mild non-purulent cellulitis, use an antibiotic active against streptococci, as they are the most common causative organisms 1, 2, 3
• First-line oral options include:
  • Penicillin 2
  • Amoxicillin 2
  • Dicloxacillin (125-250 mg every 6 hours) 1, 4
  • Cephalexin (500 mg four times daily) 1, 2
  • Clindamycin 1, 2
• For moderate to severe cellulitis with systemic signs of infection, consider coverage for both streptococci and methicillin-susceptible S. aureus (MSSA) 1, 2

MRSA Considerations

• MRSA is an unusual cause of typical cellulitis, and treatment specifically targeting MRSA is usually unnecessary 1
• Consider MRSA coverage only in specific situations:
  • Cellulitis associated with penetrating trauma 1
  • Evidence of MRSA infection elsewhere 1
  • History of injection drug use 1
  • Presence of purulent drainage 1
  • Systemic inflammatory response syndrome (SIRS) 1
• If MRSA coverage is needed, options include:
  • Oral: doxycycline, clindamycin, or trimethoprim-sulfamethoxazole 1
  • Intravenous: vancomycin, daptomycin, linezolid, or telavancin 1

Duration of Treatment

• A 5-day course of antimicrobial therapy is recommended for uncomplicated cellulitis 1, 2
• Extend treatment only if the infection has not improved within the initial 5-day period 1, 2
• For severe infections, treatment may need to be continued for at least 48 hours after the patient becomes afebrile, asymptomatic, and cultures are negative 4

Treatment Setting

• Outpatient therapy is appropriate for patients without SIRS, altered mental status, or hemodynamic instability 1, 2
• Consider hospitalization if:
  • Patient has SIRS, altered mental status, or hemodynamic instability 1, 2
  • There is concern for deeper or necrotizing infection 1, 2
  • Patient has poor adherence to therapy 1, 2
  • Patient is severely immunocompromised 1, 2
  • Patient is failing outpatient treatment 2

Adjunctive Measures

• Elevate the affected leg to promote gravity drainage of edema and inflammatory substances 1, 2
• Consider systemic corticosteroids (e.g., prednisone 40 mg daily for 7 days) in non-diabetic adult patients to reduce inflammation and hasten resolution 1, 5
• Anti-inflammatory agents like ibuprofen may help hasten resolution of inflammation 6
• Treat any predisposing factors such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 1, 2
• Carefully examine interdigital toe spaces for fissuring, scaling, or maceration that may harbor pathogens 1

Prevention of Recurrence

• Identify and treat predisposing conditions such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 1, 2, 7
• For patients with 3-4 episodes of cellulitis per year despite treatment of predisposing factors, consider prophylactic antibiotics 1, 2:
  • Oral penicillin or erythromycin twice daily for 4-52 weeks 1, 2
  • Intramuscular benzathine penicillin every 2-4 weeks 1, 2

Common Pitfalls to Avoid

• Don't routinely obtain blood cultures or tissue aspirates for typical cases of cellulitis 1, 2
• Don't extend treatment unnecessarily beyond 5 days if clinical improvement has occurred 1, 2
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 1, 8
• Don't confuse cellulitis with pseudocellulitis conditions like venous stasis dermatitis, contact dermatitis, or lymphedema 8