What is the best treatment for a skin abscess?

Best Treatment for Skin Abscess

Incision and drainage (I&D) is the primary and definitive treatment for skin abscesses, and antibiotics should NOT be routinely prescribed for simple abscesses after adequate drainage. 1, 2

Primary Treatment: Incision and Drainage

All cutaneous abscesses require incision and drainage as the cornerstone of therapy. 1, 2, 3 This is a strong recommendation based on consensus guidelines from the World Journal of Emergency Surgery and the Infectious Diseases Society of America. 2, 3

Key Technical Points:

• Make the incision as close as possible to the anal verge (for perianal abscesses) or over the point of maximal fluctuance to minimize fistula length while ensuring adequate drainage. 1
• Do NOT pack the wound routinely - simply cover with dry sterile gauze, as packing causes more pain without improving healing outcomes. 2
• Do NOT attempt needle aspiration - it has only a 25% overall success rate and less than 10% success with MRSA infections. 2, 3
• Ensure complete drainage to avoid the high recurrence rate (up to 44%) associated with inadequate drainage, loculations, or horseshoe-type abscesses. 1

When Antibiotics Are NOT Needed

For simple abscesses treated with adequate I&D, do NOT prescribe antibiotics. 1, 2 This is critical to avoid contributing to antibiotic resistance without improving patient outcomes.

Simple abscesses are defined as those with: 2

• Induration and erythema limited to the defined abscess area
• No extension into deeper tissues or multiloculated spread
• Absence of systemic signs of infection

When to ADD Antibiotics

Add antibiotics only when specific high-risk features are present: 2, 3

Systemic Inflammatory Response Syndrome (SIRS) Criteria:

• Temperature >38°C or <36°C
• Heart rate >90 beats/min
• Respiratory rate >24 breaths/min
• WBC >12,000 or <4,000 cells/µL

Other High-Risk Indications: 2

• Severe or extensive disease involving multiple infection sites
• Rapid progression with associated cellulitis
• Immunocompromised patients
• Extremes of age
• Abscess in difficult-to-drain areas (perianal, perirectal, IV drug injection sites)
• Associated septic phlebitis
• Incomplete source control
• Lack of response to I&D alone

Antibiotic Selection When Indicated

For outpatient empiric coverage of community-acquired MRSA (CA-MRSA), use: 2

• Trimethoprim-sulfamethoxazole (TMP-SMX) 320/1,600 mg twice daily for 7 days (first-line based on high-quality RCT evidence) 4, 5
• Clindamycin
• Doxycycline or minocycline
• Linezolid

Duration: 5-10 days when antibiotics are used. 2

Evidence Supporting TMP-SMX:

A large randomized trial of 1,057 patients demonstrated that TMP-SMX resulted in 92.9% clinical cure versus 85.7% with placebo at 7-14 days, with benefits seen across all lesion sizes and regardless of guideline antibiotic criteria. 4, 5 The treatment effect was greatest in patients with history of MRSA infection, fever, and positive MRSA culture. 4

Complex Abscesses Requiring Different Management

For complex abscesses (perianal, perirectal, IV drug injection sites, or those with significant surrounding cellulitis), use I&D PLUS empiric broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria. 2

Perianal/Perirectal Abscesses: 1, 2

• Drain surgically with identification of fistula tracts
• Timing dictated by presence and severity of sepsis
• Emergent drainage required if sepsis, severe sepsis, septic shock, immunosuppression, diabetes, or diffuse cellulitis present
• Otherwise, perform drainage within 24 hours

Culture Recommendations

Gram stain and culture of pus are recommended for carbuncles and abscesses, but treatment without these studies is reasonable in typical cases. 2 Culture results guide antibiotic adjustment if treatment fails. 2

Critical Pitfalls to Avoid

• Do NOT use rifampin as single agent or adjunctive therapy for skin abscesses. 2
• Do NOT routinely prescribe antibiotics for simple abscesses after adequate I&D - this contributes to resistance without improving outcomes. 1, 2
• Do NOT use fluoroquinolones for MRSA coverage - they are inadequate. 2
• Do NOT rely on antibiotics alone for abscesses that require drainage - source control via I&D remains essential even when inflammatory markers are elevated. 3

Small Furuncles (Boils)

Small furuncles frequently rupture and drain spontaneously, especially with moist heat application. 3 However, large furuncles and all carbuncles should be treated promptly with I&D rather than awaiting spontaneous resolution. 3