What is the recommended empirical antibiotic therapy for a cutaneous abscess with associated systemic infection before culture results are available?

Empirical Antibiotic Therapy for Cutaneous Abscess with Systemic Infection

For a cutaneous abscess with associated systemic infection before culture results are available, trimethoprim-sulfamethoxazole (TMP-SMX) is recommended as empirical therapy along with incision and drainage. 1

Initial Management Approach

• Incision and drainage is the primary treatment for cutaneous abscesses, but antibiotic therapy is necessary when there are signs of systemic illness 1
• Antibiotic therapy is specifically indicated for abscesses with:
  • Severe or extensive disease (multiple infection sites)
  • Rapid progression with associated cellulitis
  • Signs and symptoms of systemic illness
  • Associated comorbidities or immunosuppression
  • Extremes of age
  • Abscess in difficult-to-drain areas (face, hand, genitalia)
  • Associated septic phlebitis
  • Lack of response to incision and drainage alone 1

Recommended Empirical Antibiotic Options for Outpatients

• For empirical coverage of community-acquired MRSA (CA-MRSA) in outpatients with skin and soft tissue infections (SSTIs), the following oral options are recommended:

  • Trimethoprim-sulfamethoxazole (TMP-SMX) (A-II) 1
  • Clindamycin (A-II) 1
  • Tetracycline (doxycycline or minocycline) (A-II) 1
  • Linezolid (A-II) 1

• If coverage for both β-hemolytic streptococci and CA-MRSA is desired:

  • Clindamycin alone (A-II) 1
  • TMP-SMX or a tetracycline in combination with a β-lactam (e.g., amoxicillin) (A-II) 1
  • Linezolid alone (A-II) 1

Duration of Therapy

• 5-10 days of antibiotic therapy is recommended for outpatients with purulent cellulitis, with duration individualized based on clinical response 1
• Recent evidence suggests that a full course (7-10 days) of TMP-SMX results in better outcomes than shorter courses, particularly for MRSA infections 2

Evidence Supporting TMP-SMX for Abscesses

• A large randomized trial demonstrated that TMP-SMX (at doses of 320 mg and 1600 mg, respectively, twice daily for 7 days) was superior to placebo in patients with drained abscesses 3
• Clinical cure rates were significantly higher with TMP-SMX (92.9%) compared to placebo (85.7%) 3, 4
• TMP-SMX was also associated with lower rates of:
  • Subsequent surgical drainage procedures (3.4% vs. 8.6%)
  • Skin infections at new sites (3.1% vs. 10.3%)
  • Infections in household members (1.7% vs. 4.1%) 3

Management of Hospitalized Patients

• For hospitalized patients with complicated SSTIs (deeper soft-tissue infections, surgical/traumatic wound infection, major abscesses, cellulitis), empirical therapy for MRSA should be considered pending culture data 1
• Intravenous options include:
  • Vancomycin (A-I) 1
  • Linezolid 600 mg IV twice daily (A-I) 1
  • Daptomycin 4 mg/kg IV once daily (A-I) 1, 5
  • Telavancin 10 mg/kg IV once daily (A-I) 1
  • Clindamycin 600 mg IV three times a day (A-III) 1

Special Considerations

• Obtain cultures from abscesses in patients:

  • Treated with antibiotic therapy
  • With severe local infection or signs of systemic illness
  • Who have not responded adequately to initial treatment
  • When there is concern for a cluster or outbreak 1

• Caution when using TMP-SMX in:

  • Elderly patients receiving concurrent inhibitors of the renin-angiotensin system
  • Patients with chronic renal insufficiency (increased risk of hyperkalemia)
  • Pregnant women in the third trimester
  • Infants younger than 2 months of age 1

Common Pitfalls to Avoid

• Rifampin should not be used as a single agent or as adjunctive therapy for the treatment of SSTIs 1
• Failure to obtain cultures in patients with systemic signs of infection may lead to inadequate antimicrobial coverage 1
• Inadequate duration of therapy (particularly with MRSA infections) can lead to treatment failure and recurrence 2
• Relying solely on incision and drainage without antibiotics when systemic signs are present can lead to treatment failure 1