What is the recommended management for an abscess, including incision and drainage (I&D) and antibiotic (abx) treatment?

Management of Abscess: Incision & Drainage and Antibiotic Treatment

Primary Treatment Strategy

Incision and drainage (I&D) is the primary and essential treatment for cutaneous abscesses, and for simple, uncomplicated abscesses, I&D alone without antibiotics is adequate. 1

Simple vs. Complex Abscesses: Treatment Algorithm

Simple Abscesses (I&D Alone is Sufficient)

• Simple superficial abscesses or boils require only incision and drainage without routine antibiotic therapy 1, 2
• Simple abscesses are defined as single-site infections without surrounding cellulitis, in immunocompetent patients, without systemic signs of infection 1
• For abscesses ≤5 cm, I&D alone provides adequate treatment in most cases 3, 4

When to Add Antibiotics (Complex Abscesses)

Antibiotic therapy is mandatory when any of the following conditions are present: 1

• Severe or extensive disease (multiple sites of infection) 1
• Rapid progression with associated cellulitis 1
• Signs of systemic illness (fever, tachycardia, hypotension) 1
• Immunosuppression or significant comorbidities 1
• Extremes of age (very young or elderly) 1
• Difficult-to-drain locations (face, hand, genitalia) 1
• Associated septic phlebitis 1
• Lack of response to I&D alone 1
• Perianal, perirectal, or IV drug injection site abscesses 2
• Incomplete source control 2

Antibiotic Selection for Outpatient Management

For CA-MRSA Coverage (Most Common Pathogen)

First-line empiric oral antibiotic options include: 1

• Clindamycin (preferred for monotherapy covering both MRSA and streptococci) 1
• Trimethoprim-sulfamethoxazole (TMP-SMX) 1
• Doxycycline or minocycline 1
• Linezolid 1

When Dual Coverage Needed (MRSA + β-hemolytic Streptococci)

• Clindamycin alone (covers both) 1
• TMP-SMX or tetracycline PLUS a β-lactam (e.g., amoxicillin or cephalexin) 1
• Linezolid alone (covers both) 1

Evidence Supporting Antibiotic Use

• A high-quality 2017 placebo-controlled trial demonstrated that clindamycin or TMP-SMX added to I&D improved cure rates from 68.9% (placebo) to 83.1% (clindamycin) and 81.7% (TMP-SMX) in abscesses ≤5 cm 3
• This benefit was restricted to patients with S. aureus infection 3
• Clindamycin reduced new infections at 1 month (6.8%) compared to TMP-SMX (13.5%) or placebo (12.4%), though it had more adverse events (21.9% vs 11.1% for TMP-SMX) 3

Contradictory Evidence

• A 2018 study showed no statistical difference in resolution rates between antibiotics (96%) versus placebo (93%) after I&D for uncomplicated abscesses 5
• However, this conflicts with the higher-quality 2017 NEJM trial, which should take precedence 3

Duration of Therapy

• 5 to 10 days of antibiotic therapy is recommended for skin and soft tissue infections requiring antibiotics 1

Surgical Technique Considerations

Drainage Procedure

• Thorough evacuation of pus and probing the cavity to break up loculations is essential 2
• Large abscesses should be drained with multiple counter incisions rather than a single long incision to prevent step-off deformity and delayed healing 2
• Packing wounds larger than 5 cm may reduce recurrence, though simple dry dressing coverage is usually effective 2, 4

Size-Based Management

• Abscesses >5 cm may require more aggressive management, including consideration of surgical intervention 2

Complex/Intra-Abdominal Abscesses

Antibiotic Coverage Requirements

• Complex abscesses require empiric broad-spectrum antibiotics covering gram-positive, gram-negative, and anaerobic bacteria 2
• Inadequate antibiotic coverage after I&D of complicated peri-rectal abscess results in a six-fold increase in readmission rates (28.6% vs 4%) 6

Antibiotic Penetration Considerations

• Piperacillin/tazobactam, cefepime, and metronidazole provide adequate concentrations in most abscesses 7
• Vancomycin and ciprofloxacin levels are inadequate in most abscesses and should be avoided as monotherapy 7

Critical Pitfalls to Avoid

• Never use rifampin as single agent or adjunctive therapy for skin and soft tissue infections 1
• Do not rely on antibiotics alone without drainage for drainable abscesses—this is inadequate source control 1, 2
• Incision and drainage must be performed in conjunction with antibiotic therapy when indicated 8, 9
• Culture data should guide definitive therapy, but empiric coverage for MRSA is essential in the current era 1
• For perirectal abscesses, failure to provide adequate polymicrobial coverage (gram-positive, gram-negative, and anaerobic) significantly increases recurrence 6