What antibiotics are prescribed for an axillary abscess (abscess in the arm pit) without drainage?

Antibiotic Treatment for Axillary Abscess Without Drainage

For an axillary abscess without drainage, the recommended antibiotic treatment is trimethoprim-sulfamethoxazole (TMP-SMX) as it provides excellent coverage against community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), which is the most common pathogen in skin abscesses. 1

Assessment and Antibiotic Selection

First-line Treatment Options:

• Trimethoprim-sulfamethoxazole (TMP-SMX): 1-2 DS tablets PO twice daily for 7-10 days 1, 2
  • Highly effective against CA-MRSA
  • Limited activity against β-hemolytic streptococci
  • Not recommended in pregnant women in third trimester or children <2 months

Alternative Options:

• Clindamycin: 300-450 mg PO three times daily for 7-10 days 1, 3

  • Provides coverage for both MRSA and β-hemolytic streptococci
  • Higher risk of Clostridioides difficile-associated disease
  • FDA-approved for serious skin and soft tissue infections 3

• Doxycycline: 100 mg PO twice daily for 7-10 days 1

  • Effective against MRSA
  • Limited activity against streptococci
  • Not recommended for children <8 years or pregnant women

• Linezolid: 600 mg PO twice daily for 7-10 days 1, 4

  • Highly effective but more expensive
  • Consider for severe infections or treatment failures

Evidence Supporting Antibiotic Treatment

Recent clinical trials have demonstrated that antibiotics significantly improve outcomes in skin abscesses, even without drainage:

• A large randomized controlled trial showed that TMP-SMX resulted in higher cure rates (80.5%) compared to placebo (73.6%) in patients with skin abscesses 2

• Another multicenter trial demonstrated that both clindamycin (83.1%) and TMP-SMX (81.7%) were superior to placebo (68.9%) for treating skin abscesses 5

• For MRSA-specific abscesses, a pediatric study showed that a 10-day course of TMP-SMX was more effective than a 3-day course in preventing treatment failure and recurrence 6

Clinical Considerations

When to Consider Broader Coverage:

• If there is extensive surrounding cellulitis, consider adding coverage for β-hemolytic streptococci:
  • TMP-SMX plus amoxicillin 1
  • Clindamycin alone (covers both MRSA and streptococci) 1

Treatment Duration:

• 7-10 days is the recommended duration for most uncomplicated abscesses 1
• Evaluate response after 2-3 days; if no improvement, consider:
  • Obtaining cultures if not previously done
  • Changing antibiotics based on susceptibility
  • Reassessing need for surgical drainage

Important Caveats:

• While antibiotics are recommended for this case, incision and drainage remains the primary treatment for abscesses when feasible 1
• Axillary location is considered a "difficult to drain area" which specifically warrants antibiotic therapy even for smaller abscesses 1
• A case report specifically of axillary MRSA abscess showed successful treatment with TMP-SMX after failed treatment with cephalexin 7

Follow-up Recommendations:

• Reassess in 48-72 hours to evaluate response
• Complete the full antibiotic course even if symptoms improve
• Consider imaging (ultrasound) if the abscess is not improving to determine if drainage is needed
• For recurrent abscesses, consider decolonization with intranasal mupirocin and chlorhexidine washes

In conclusion, while surgical drainage is typically the cornerstone of abscess management, an axillary abscess without drainage should be treated with TMP-SMX as first-line therapy due to the high prevalence of CA-MRSA in skin abscesses and strong evidence supporting its efficacy.