Treatment of Subcutaneous Abscesses
Incision and drainage (I&D) is the cornerstone of treatment for subcutaneous abscesses, with antibiotics generally reserved for specific clinical scenarios. 1, 2
Primary Treatment Approach
Incision and Drainage Procedure
- Obtain wound culture before or during the procedure to identify causative organisms and determine antibiotic susceptibility 2
- Make an adequate incision to allow complete drainage of purulent material
- Probe the cavity to break up loculations
- Simply cover the surgical site with a dry dressing (most effective post-drainage wound management) 1, 2
- Packing is generally unnecessary and may cause more pain without improving healing outcomes 1, 3
Alternative Drainage Techniques
- Deroofing technique (removing the skin overlying the abscess) is preferred when possible as it's associated with lower recurrence rates compared to simple I&D 2
- Loop drainage using a modified sterile glove may offer benefits such as decreased pain, no need for packing changes, and fewer follow-up visits 4
Antibiotic Therapy
When to Use Antibiotics
Antibiotics should be added to I&D in patients with:
- Systemic inflammatory response syndrome (SIRS): temperature >38°C or <36°C, tachypnea >24 breaths/minute, tachycardia >90 beats/minute, or WBC >12,000 or <400 cells/μL 1
- Markedly impaired host defenses 1
- Extensive surrounding cellulitis
- Immunosuppression or diabetes mellitus 2
Antibiotic Selection
If antibiotics are indicated, recommended options include:
- First-line: Amoxicillin-clavulanate 875/125 mg PO twice daily 2
- For MRSA coverage:
- Trimethoprim-sulfamethoxazole (TMP-SMX) 160-320/800-1600 mg PO q12h
- Doxycycline 100 mg PO q12h (avoid in children <8 years and pregnant women) 2
Follow-up Care
- Re-evaluate in 48-72 hours to assess healing progress 2
- Warm soaks can promote drainage and healing 2
- Analgesics (acetaminophen or NSAIDs) for pain management 2
- Complete 5-10 day course of antibiotics if prescribed 1
Management of Recurrent Abscesses
- Search for local causes (pilonidal cyst, hidradenitis suppurativa, foreign material) 1
- Early drainage and culture of recurrent abscesses 1
- Consider 5-day decolonization regimen for recurrent S. aureus infections:
- Intranasal mupirocin twice daily
- Daily chlorhexidine washes
- Daily decontamination of personal items (towels, sheets, clothes) 1
- Consider complete excision of the cyst once acute inflammation resolves to prevent recurrence 2
Special Considerations
- Fit, immunocompetent patients with small abscesses and no systemic signs can be managed as outpatients 2
- Patients with sepsis, immunosuppression, or diabetes require emergent drainage 2
- Inadequate drainage is associated with high recurrence rates (up to 44%) 2
- Multiple studies have shown that antibiotics are not necessary for uncomplicated subcutaneous abscesses after proper I&D 5
- Ultrasonographically guided needle aspiration is not recommended (successful in only 25% of cases overall and <10% with MRSA infections) 1
Common Pitfalls to Avoid
- Failing to obtain cultures before starting antibiotics
- Inadequate drainage or probing of loculations
- Unnecessary use of antibiotics for simple, adequately drained abscesses
- Overlooking potential underlying causes in recurrent cases
- Inadequate follow-up (should reassess within 48-72 hours)
- Misdiagnosis of other entities presenting as abscesses (e.g., mycotic aneurysms) 6