What is the recommended treatment for cellulitis?

Treatment of Cellulitis

The recommended first-line treatment for uncomplicated cellulitis is prompt administration of antibiotics effective against beta-hemolytic streptococci and Staphylococcus aureus, with options including amoxicillin-clavulanate or clindamycin 600 mg orally three times daily for 5-10 days. 1

Antibiotic Selection Algorithm

For Uncomplicated Cellulitis (Outpatient):

1. First-line options:

   • Amoxicillin-clavulanate (Augmentin) 1
   • Clindamycin 600 mg orally three times daily 1

2. Alternative options:

   • TMP-SMX plus amoxicillin (Note: TMP-SMX alone should be avoided due to poor activity against streptococci) 1
   • Doxycycline or minocycline (contraindicated in children <8 years) 1
   • Linezolid 600 mg twice daily 1

3. Duration of therapy:

   • 5-6 days is as effective as longer courses for uncomplicated cases 1, 2
   • Standard duration is 5-10 days, individualized based on clinical response 1

For Complicated/Severe Cellulitis (Inpatient):

1. Immediate hospitalization with:
   • IV vancomycin (for MRSA coverage) plus coverage for other pathogens 1
   • For severe infections near the perineum: ceftriaxone plus metronidazole or a fluoroquinolone plus metronidazole 1

Pathogen Considerations

• The majority of non-purulent, uncomplicated cellulitis cases are caused by beta-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus 3
• When MRSA risk factors are present, consider adding or switching to an MRSA-active agent such as:
  • Vancomycin (for severe cases requiring IV therapy)
  • Linezolid
  • Clindamycin (if local resistance rates are low)
  • TMP-SMX (must be combined with streptococcal coverage) 1

Management of Abscesses

• For abscesses with significant cellulitis: incision and drainage plus antibiotic therapy 1
• Cultures should be obtained from abscesses and purulent drainage to guide therapy 1
• Empiric broad-spectrum antibiotic therapy may be needed for complex abscesses 1

Follow-up and Monitoring

• Daily follow-up until definite improvement is noted 1
• Watch for signs of treatment failure:
  • Increasing erythema or edema
  • Failure to improve after 48-72 hours of appropriate therapy
  • Development of systemic symptoms

Special Considerations

1. Adjunctive measures:

   • Consider systemic corticosteroids in select adult patients to hasten resolution (contraindicated in diabetics and pregnant women) 1
   • Reduce underlying edema through elevation, compression stockings, and diuretic therapy if appropriate 1

2. Prevention of recurrence:

   • Identify and treat predisposing conditions: edema, obesity, eczema, venous insufficiency, and local trauma sites 1, 4
   • Consider prophylactic antibiotics for patients with 3-4 episodes per year despite treatment of predisposing factors 1

Common Pitfalls to Avoid

1. Diagnostic errors:

   • Cellulitis is frequently confused with venous insufficiency, eczema, deep vein thrombosis, and gout 5
   • Ensure proper diagnosis before initiating antibiotics

2. Treatment errors:

   • Using TMP-SMX alone for non-purulent cellulitis (poor streptococcal activity) 1
   • Using tetracyclines in children under 8 years of age 1
   • Failing to obtain cultures when abscesses or purulent drainage are present 1
   • Not addressing underlying predisposing conditions, leading to recurrence 4

3. Follow-up errors:

   • Inadequate monitoring for clinical improvement
   • Not recognizing when to escalate care for treatment failure

The evidence strongly supports a 5-day course of appropriate antibiotics for uncomplicated cellulitis, which is as effective as a 10-day course 2, potentially reducing antibiotic exposure and improving compliance.