What is the treatment plan for a 31-year-old female with bilateral axillary swellings, painful and red, with 5x3 cm pus evacuated, culture/sensitivity (C/S) showing Porphyromonas, Prevotella, and Staphylococcus aureus?

Management of Bilateral Axillary Abscesses with Polymicrobial Infection

The optimal treatment for this 31-year-old female with bilateral axillary abscesses involves incision and drainage with healing by secondary intention, combined with appropriate antibiotic therapy targeting the polymicrobial infection including Porphyromonas, Prevotella, and Staphylococcus aureus.

Surgical Management

The cornerstone of treatment for these axillary abscesses is proper surgical intervention:

• Incision and drainage is the primary and most important therapeutic intervention for abscesses, with strong evidence supporting this approach 1
• Complete evacuation of all purulent material (5x3 cc of pus already evacuated) is essential for effective treatment 1
• Healing by secondary intention is strongly recommended to prevent premature closure that could lead to recurrent abscess formation, especially with polymicrobial infections 1

Primary closure or flap procedures are not recommended in this case due to the active infection and risk of wound breakdown or recurrent abscess formation.

Antimicrobial Therapy

Given the polymicrobial nature of the infection with anaerobes (Porphyromonas and Prevotella) and Staphylococcus aureus, appropriate antibiotic therapy is essential:

• Amoxicillin-clavulanate (875/125 mg PO twice daily) is the first-line treatment for mixed aerobic-anaerobic infections 1, 2
• Alternative regimens include:
  • Clindamycin (300-450 mg PO four times daily) which has excellent activity against both S. aureus and anaerobes like Prevotella and Porphyromonas 3, 4
  • For MRSA concerns: Trimethoprim-sulfamethoxazole plus metronidazole (to cover anaerobes) 5

Duration of therapy should be 7-14 days, with longer courses needed due to the extensive bilateral involvement and significant purulence 5, 1.

Rationale for Treatment Recommendation

1. The Infectious Diseases Society of America guidelines strongly recommend incision and drainage as the primary treatment for abscesses 5

2. Healing by secondary intention is preferred over primary closure because:

   • Active infection with multiple bacterial species increases risk of wound breakdown
   • Continued drainage is needed to prevent recurrent abscess formation 1
   • The presence of anaerobes (Prevotella and Porphyromonas) indicates deeper tissue involvement that requires open healing 4

3. Studies show that β-lactamase production is common in Prevotella and Porphyromonas species (38% of isolates), making amoxicillin-clavulanate or clindamycin more appropriate than simple penicillins 6, 4, 2

Follow-up and Monitoring

• Regular wound care with cleaning and dressing changes until complete healing
• Reassessment after 48-72 hours to ensure adequate response to treatment
• Monitor for signs of systemic infection (fever >38.5°C, tachycardia) 1
• Consider culture-directed antibiotic adjustment if clinical improvement is not evident within 48-72 hours

Special Considerations

• Bilateral involvement suggests a possible underlying condition or predisposition that may need further evaluation
• Good hygiene practices are essential to prevent recurrence
• Pain management with acetaminophen or NSAIDs as needed

In conclusion, option D (healing by secondary intention) combined with appropriate antimicrobial therapy is the optimal approach for this patient with bilateral axillary abscesses with polymicrobial infection.