What is the first-line treatment for skin abscesses?

First-Line Treatment for Skin Abscesses

Incision and drainage (I&D) is the definitive first-line treatment for skin abscesses and is sufficient as monotherapy for most uncomplicated cases in immunocompetent patients. 1, 2, 3

Primary Treatment: Incision and Drainage

• I&D alone is adequate for simple abscesses without the need for antibiotics in immunocompetent patients 1, 2, 3
• Post-procedure wound care requires only a dry sterile dressing—wound packing causes more pain without improving healing and should be avoided 1, 3
• Needle aspiration is not recommended, with only a 25% success rate overall and less than 10% success with MRSA 3, 4
• For very small furuncles, moist heat application may promote spontaneous drainage and could be sufficient 1

When Antibiotics Should Be Added to I&D

Antibiotics are indicated when any of the following are present:

• Systemic inflammatory response syndrome (SIRS): temperature >38°C or <36°C, tachypnea >24 breaths/minute, tachycardia >90 beats/minute, or WBC >12,000 or <4,000 cells/µL 1, 3
• Significant surrounding cellulitis extending beyond the abscess borders 1, 2, 3
• Immunocompromised patients or markedly impaired host defenses 1, 2, 3
• Incomplete source control after drainage 1, 2, 3
• High-risk locations including face, hands, or genitalia 1
• Abscess size >5 cm (associated with higher hospitalization risk) 5
• Extremes of age or presence of comorbidities 3

Antibiotic Selection When Indicated

For Community-Acquired MRSA (CA-MRSA) Coverage:

First-line oral options include:

• Trimethoprim-sulfamethoxazole (TMP-SMX): 320/1,600 mg twice daily for adults 1, 3, 6
• Clindamycin: 150-450 mg every 6 hours for adults (based on severity); 8-20 mg/kg/day divided into 3-4 doses for children 1, 3, 7
• Doxycycline or minocycline (not for children <8 years) 1, 3
• Linezolid (reserved for more severe cases) 1, 3

For Non-MRSA Infections:

• Beta-lactams (penicillinase-resistant penicillins or first-generation cephalosporins) when streptococci are suspected 1, 3

Duration:

• 5-10 days is the typical duration when antibiotics are indicated 1, 3
• For MRSA infections specifically, 10 days of TMP-SMX is superior to 3 days in reducing treatment failure (10.1% rate difference) and recurrence within 1 month (10.3% rate difference) 8

Complex Abscesses Requiring Special Management

Complex abscesses (perianal/perirectal, IV drug injection sites, multiloculated, or with deep tissue extension) require:

• Prompt surgical drainage plus empiric broad-spectrum antibiotics covering Gram-positive, Gram-negative, and anaerobic bacteria 9, 2, 3
• Perianal/perirectal abscesses need identification of fistula tracts during drainage 9, 3
• IV drug users require evaluation for endocarditis if systemic signs persist, radiography to rule out foreign bodies, duplex sonography for vascular complications, and screening for HIV/HCV/HBV 9, 3

Culture Recommendations

• Not routinely needed for typical small abscesses 1
• Obtain cultures in recurrent infections, treatment failures, immunocompromised patients, and severe or atypical presentations 1, 3

Critical Pitfalls to Avoid

• Do not prescribe antibiotics routinely for simple abscesses after adequate I&D—this contributes to resistance without improving outcomes 2, 3
• Do not pack wounds routinely—evidence shows no benefit and increased pain 1, 3
• Do not use rifampin as single agent or adjunctive therapy 3
• Do not use fluoroquinolones for MRSA coverage—they are inadequate 3
• Do not assume all small abscesses need antibiotics—even with MRSA, I&D alone is effective for abscesses <5 cm in immunocompetent children 5
• Do not underestimate MRSA impact—CA-MRSA decreases success rates of both I&D (28% difference) and needle aspiration (47% difference) 4