Recommended Oral Antibiotic Treatment After Incision and Drainage
Primary Recommendation
For simple cutaneous abscesses after incision and drainage in adults without sulfa allergy, normal renal function, and not pregnant, prescribe trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily for 5-10 days. 1
When Antibiotics Are Indicated
Antibiotics should be added to incision and drainage when any of the following conditions are present: 2, 1
- Severe or extensive disease involving multiple sites of infection 2
- Rapid progression with associated cellulitis 2
- Signs of systemic illness (fever, tachycardia, hypotension) 2
- Comorbidities or immunosuppression (diabetes, HIV, malignancy) 2
- Extremes of age (very young or elderly) 2
- Difficult-to-drain locations (face, hand, genitalia) 2
- Associated septic phlebitis 2
- Lack of response to incision and drainage alone 2
First-Line Oral Antibiotic Options for CA-MRSA Coverage
TMP-SMX is the preferred first-line agent because 95-100% of community-associated MRSA strains are susceptible in vitro. 2, 1
Alternative oral options include: 2, 1
- Doxycycline 100 mg twice daily for 5-10 days 1
- Clindamycin 300-450 mg four times daily for 5-10 days (only if local resistance rates <10%) 2, 1
- Minocycline (similar dosing to doxycycline) 2
Critical Evidence Supporting Antibiotic Use
The highest quality recent trial demonstrates clear benefit: A large multicenter randomized controlled trial of 786 patients showed that both clindamycin (83.1% cure rate) and TMP-SMX (81.7% cure rate) significantly outperformed placebo (68.9% cure rate, P<0.001 for both comparisons) when added to incision and drainage. 3 This benefit was restricted to patients with S. aureus infection. 3
TMP-SMX specifically reduces recurrence: Among initially cured patients, new infections at 1 month were significantly less common with clindamycin (6.8%) compared to TMP-SMX (13.5%, P=0.03) or placebo (12.4%). 3 However, adverse events were more frequent with clindamycin (21.9%) than TMP-SMX (11.1%). 3
When TMP-SMX Alone Is Insufficient
If coverage for both β-hemolytic streptococci and CA-MRSA is needed (e.g., purulent cellulitis with surrounding non-purulent cellulitis), use: 2
- TMP-SMX plus amoxicillin 500 mg three times daily 4
- Clindamycin alone (covers both organisms) 2
- Doxycycline plus amoxicillin 2
TMP-SMX should never be used as monotherapy for cellulitis because it lacks reliable activity against β-hemolytic streptococci. 2, 4
Treatment Duration
5-10 days of therapy is recommended for uncomplicated abscesses requiring antibiotics. 2, 1 For MRSA-positive abscesses specifically, 10 days is superior to 3 days: pediatric data show that 10-day TMP-SMX courses reduce treatment failure (P=0.03) and 1-month recurrence (P=0.046) compared to 3-day courses in MRSA infections. 5
Critical Pitfalls to Avoid
Never use rifampin as monotherapy or adjunctive therapy for skin abscesses—resistance develops rapidly without proven benefit. 2, 1
Verify local clindamycin resistance rates before empirical use; clindamycin should only be used if local resistance is <10%. 1
Do not use TMP-SMX in pregnant women in the third trimester (pregnancy category C/D) or in infants <2 months of age. 2
Caution with TMP-SMX in elderly patients receiving renin-angiotensin system inhibitors or those with chronic renal insufficiency due to hyperkalemia risk. 2
When Simple Abscess May Not Need Antibiotics
For truly uncomplicated small abscesses (<5 cm) without any of the high-risk features listed above, incision and drainage alone may be adequate. 2 Multiple observational studies show 85-90% cure rates with drainage alone. 2 However, the benefit of antibiotics in preventing new lesions (as demonstrated in the highest quality trial) 3 supports their use even in simpler cases when the patient meets standard criteria.
When to Hospitalize for IV Therapy
Admit for IV vancomycin (with or without broad-spectrum β-lactam coverage) if: 4, 1