Antibiotic Selection for Recurrent Abscess After Doxycycline Failure
For this recurrent abscess that failed doxycycline treatment 5 weeks ago, you should drain the abscess, obtain cultures, and treat with either trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily or clindamycin 300-450 mg three times daily for 5-10 days, followed by a 5-day decolonization regimen. 1
Primary Management Steps
Immediate Surgical Intervention
- Incision and drainage remains the cornerstone of treatment for all abscesses, regardless of antibiotic therapy 2
- Obtain cultures from the drained abscess to identify the causative pathogen and guide antibiotic selection 1
- Before initiating antibiotics, search for underlying causes perpetuating recurrence such as pilonidal cyst, hidradenitis suppurativa, or retained foreign material 2, 1
Antibiotic Selection Strategy
First-line oral options for empiric MRSA coverage:
- Trimethoprim-sulfamethoxazole (TMP-SMX): 160-320/800-1600 mg (1-2 double-strength tablets) twice daily 2
- Clindamycin: 300-450 mg three times daily (if local resistance rates <10%) 2
- Minocycline: 200 mg loading dose, then 100 mg twice daily 2, 3
Why not doxycycline again? Since the patient already failed doxycycline treatment, switching to an alternative agent is warranted. While doxycycline and TMP-SMX are both recommended first-line agents 2, minocycline may be more reliably effective than doxycycline for CA-MRSA when doxycycline has failed 3. However, TMP-SMX or clindamycin remain the most evidence-based alternatives 2, 4.
Treatment Duration
- Standard duration is 5-10 days of antibiotic therapy 2, 1
- Extend treatment if the infection has not improved within this timeframe 2, 1
Critical Indications for Antibiotic Use
You must use antibiotics (in addition to drainage) if any of the following are present: 2, 1
- Surrounding cellulitis or erythema extending >2 cm beyond the abscess margin
- Systemic signs of infection (fever, tachycardia, hypotension)
- Immunocompromised status
- Multiple abscesses or rapid progression
- Abscess in difficult-to-drain location (face, hand, genitalia)
- Extremes of age
- Comorbidities (diabetes, HIV/AIDS)
- Failed incision and drainage alone
Decolonization Protocol
After completing the acute antibiotic course, implement a 5-day decolonization regimen: 1
- Intranasal mupirocin 2% ointment twice daily for 5 days 2, 1
- Daily chlorhexidine body washes 2, 1
- Daily decontamination of personal items (towels, sheets, razors) 2, 1
The IDSA recommends considering decolonization given the low risk and potential benefit in preventing recurrences 1. While older studies showed benefit from monthly intranasal mupirocin or prolonged oral clindamycin 2, more recent data on effectiveness in the CA-MRSA era are mixed 2.
Evidence-Based Rationale
Why TMP-SMX or clindamycin over continuing doxycycline:
- A large randomized trial demonstrated that both clindamycin and TMP-SMX significantly improved cure rates (83.1% and 81.7% respectively) compared to drainage alone (68.9%, P<0.001) 4
- Clindamycin showed fewer new infections at 1-month follow-up (6.8%) compared to TMP-SMX (13.5%) 4
- However, clindamycin had more adverse events (21.9%) than TMP-SMX (11.1%) 4
- Minocycline is often more effective than doxycycline or TMP-SMX when these agents fail for CA-MRSA 3
Important Caveats
- Streptococcal coverage consideration: TMP-SMX, doxycycline, and minocycline have poorly defined activity against β-hemolytic streptococci 2. If there is concern for streptococcal infection (rapidly spreading cellulitis, no purulent drainage), clindamycin provides dual coverage 2
- Clindamycin resistance: Only use clindamycin if local resistance rates are <10% and the D-test is negative if performed 2
- Culture results: Adjust antibiotics based on culture and susceptibility results once available 1
- Recurrence risk: Multiple recurrences warrant investigation for underlying conditions and consideration of household decolonization 2, 1