Post-Procedure Care for Infected Cyst After Incision and Drainage
The primary treatment after incision and drainage of an infected cyst is to leave the wound open with regular dressing changes, allowing it to heal by secondary intention over 7-14 days, while avoiding routine wound packing. 1, 2
Wound Management
Dressing Approach
- Simply cover the surgical site with a dry sterile dressing—this is the easiest and most effective treatment. 2, 3
- Change dressings regularly until the cavity is fully healed, which typically takes 7-14 days. 2
- Do NOT routinely pack the abscess cavity after drainage, as packing is painful, costly, and does not improve healing outcomes. 1, 2
- Never close the wound primarily with sutures—the wound must remain open and heal by secondary intention. 2, 3
Critical Success Factors
- Complete and adequate drainage is more important than antibiotics for successful healing. 1, 2
- Inadequate drainage, loculations, and prolonged time from onset to incision are the main risk factors for recurrence (which can be as high as 44%). 1, 2
Antibiotic Decision-Making
When Antibiotics Are NOT Needed
Most simple drained abscesses do not require antibiotics. 1 Specifically, antibiotics are unnecessary when: 1
- Temperature <38.5°C
- Heart rate <100 beats/min
- Erythema/induration extending <5 cm from wound edge
- No systemic signs of infection
- Patient is immunocompetent
When Antibiotics ARE Indicated
Antibiotics should be administered when any of the following are present: 1, 2
- Erythema or cellulitis extending >5 cm beyond the wound margins
- Temperature ≥38.5°C or heart rate >110 beats/min
- Signs of systemic inflammatory response or sepsis (hypotension, oliguria, decreased mental alertness)
- Immunocompromised status (HIV, diabetes, immunosuppression)
- Surrounding soft tissue infection with induration
Recommended Antibiotic Regimens
For typical skin flora coverage (including anaerobes for perineal/pilonidal cysts): 1, 3
- First-line: Amoxicillin-clavulanate 875/125 mg PO twice daily
- Penicillin allergy: Clindamycin 300-450 mg PO three times daily PLUS ciprofloxacin 500 mg PO twice daily
Duration: 3
- 24-48 hours if minimal systemic signs
- 5-10 days if surrounding cellulitis or significant systemic response present
Culture and Microbiological Considerations
- Obtain cultures from the drained abscess to identify pathogens and guide antibiotic selection, especially in: 1, 2
- Immunocompromised patients
- Recurrent infections
- Patients with risk factors for MRSA (healthcare exposure, previous MRSA infection)
- Non-healing wounds
- MRSA prevalence in skin abscesses can be as high as 35%. 1
- For recurrent MRSA abscesses, use trimethoprim-sulfamethoxazole 160-320/800-1600 mg (1-2 double-strength tablets) twice daily for 5-10 days. 2
Special Considerations by Cyst Location
Pilonidal Cysts
- Antibiotics generally not necessary unless systemic signs present. 3
- When indicated, use oral antibiotics covering skin flora AND anaerobes (amoxicillin-clavulanate preferred). 3
Anorectal Abscesses
- Timing of drainage is dictated by sepsis severity—emergent drainage required for sepsis, severe sepsis, or septic shock. 1
- In absence of sepsis, drainage should ideally occur within 24 hours. 1
- Antibiotics reduce fistula formation from 24% to 16% when given for 5-10 days post-drainage. 1
Hepatic Cysts (if applicable)
- Fluoroquinolones (ciprofloxacin) and third-generation cephalosporins are standard treatment. 1
- Drainage may be needed if temperature persists >38.5°C after 48 hours on antibiotics. 1
Common Pitfalls to Avoid
- Do NOT attempt needle aspiration—it has <10% success rate with MRSA and is not recommended. 2
- Do NOT probe for fistulas during initial drainage to avoid iatrogenic complications. 1
- Do NOT use routine wound packing unless specifically indicated for hemostasis. 1, 2
- Seek underlying causes for recurrent cysts: pilonidal disease, hidradenitis suppurativa, foreign material. 2