What is the recommended treatment for an axillary abscess?

Axillary Abscess Treatment

Incision and drainage is the primary and essential treatment for axillary abscess, with antibiotics reserved for specific clinical scenarios including systemic signs of infection, extensive surrounding cellulitis (>5 cm), or immunocompromised patients. 1, 2

Primary Treatment Approach

Immediate incision and drainage must be performed for all axillary abscesses. 1, 2 This is the cornerstone of therapy and is often sufficient as monotherapy for uncomplicated cases. 1

• Simple wound coverage with sterile gauze is preferred over packing, as packing increases pain without improving healing outcomes. 1
• Wound culture should be obtained during drainage to guide subsequent antibiotic therapy if needed. 1

When Antibiotics Are NOT Required

For simple abscesses meeting ALL of the following criteria, antibiotics are unnecessary after adequate drainage: 1, 2

• Surrounding erythema <5 cm from wound margins 1
• Temperature <38.5°C 1
• Heart rate <110 beats/minute 1
• White blood cell count <12,000 cells/µL 1
• No immunocompromising conditions 2

When Antibiotics ARE Required

Add antibiotics to incision and drainage when ANY of the following are present: 1, 2

• Systemic signs: Temperature >38.5°C or heart rate >110 beats/minute 1, 2
• Extensive cellulitis: Erythema extending >5 cm beyond wound margins 1, 2
• Immunocompromised state (including diabetes mellitus) 2
• Incomplete drainage or inadequate source control 2
• Rapid progression or multiple sites of infection 1
• Difficult-to-drain locations (face, hand, genitalia) 1

Antibiotic Selection

Empiric Coverage for Community-Acquired MRSA

For outpatient oral therapy (5-10 days): 1

• First-line options: TMP-SMX, doxycycline, or clindamycin 1
• Alternative: Linezolid 1
• Clindamycin provides coverage for both MRSA and β-hemolytic streptococci 1

For Hospitalized Patients with Severe Infection

Intravenous therapy is indicated for: 1

• Vancomycin (standard dosing) 1
• Linezolid 600 mg IV twice daily 1
• Daptomycin 4 mg/kg/dose IV 1

Microbiology Considerations

• Staphylococcus aureus (including MRSA) is the most common pathogen, isolated in approximately 65% of axillary abscesses. 3
• Anaerobic bacteria are secondary invaders in approximately 23% of cases, particularly in hidradenitis suppurativa. 3
• Anaerobes produce offensive-smelling discharge; metronidazole can be added if anaerobes are suspected or confirmed. 3

Special Consideration: Hidradenitis Suppurativa

For recurrent axillary abscesses associated with hidradenitis suppurativa: 3

• Chemotherapy offers limited benefit for cure 3
• Radical surgical excision is usually required for definitive management 3
• Metronidazole may be used palliatively to control malodorous discharge 3

Monitoring and Follow-Up

Reassess within 48-72 hours for: 2

• Decreased pain and swelling 2
• Resolution of fever 2
• Reduction in erythema 2

If no improvement occurs, evaluate for: 2

• Inadequate drainage requiring repeat procedure 2
• Resistant organisms necessitating antibiotic adjustment based on culture results 2
• Deeper or more extensive infection 2

Critical Pitfalls to Avoid

• Do not rely on antibiotics alone without drainage - this will fail. 1
• Do not use needle aspiration - success rate is only 25% overall and <10% for MRSA infections. 1
• Do not use rifampin as monotherapy or adjunctive therapy for skin and soft tissue infections. 1
• Do not assume all axillary masses are simple abscesses - rare cases may represent underlying malignancy requiring biopsy if non-healing. 4