Treatment of Axillary Abscess
Incision and drainage is the primary and most important treatment for an axillary abscess, with antibiotics reserved only for patients with systemic signs of infection or specific high-risk features 1.
Primary Treatment Approach
Perform incision and drainage immediately - this is the definitive treatment and should not be delayed 1. The procedure involves:
- Opening the abscess completely
- Evacuating all purulent material
- Allowing the wound to heal by secondary intention with dressing changes
Do NOT routinely pack the wound - recent high-quality evidence shows packing increases pain without improving outcomes 2. Simply covering with a sterile dry dressing is preferred 1.
When to Add Antibiotics
Antibiotics are NOT needed for most uncomplicated axillary abscesses if 1:
- Erythema extends <5 cm beyond the abscess margin
- Temperature <38.5°C
- Heart rate <110 beats/minute
- WBC count <12,000 cells/µL
Add antibiotics active against MRSA if the patient has 1:
- Temperature >38°C or <36°C
- Heart rate >110 beats/minute
- Erythema extending >5 cm beyond margins
- Immunocompromised state
- Signs of systemic inflammatory response syndrome (SIRS)
For these cases, use MRSA-active agents such as trimethoprim-sulfamethoxazole, doxycycline, or clindamycin for a short course (typically 5-10 days) 1, 3, 2.
Culture Considerations
Obtain culture of the purulent material to guide antibiotic selection if antibiotics are needed 1. This is particularly important given:
- S. aureus (including MRSA) is the most common pathogen 4, 3
- Anaerobic bacteria can be present, especially in hidradenitis suppurativa 4
- Susceptibility patterns vary regionally
Special Considerations for Axillary Location
The axilla presents unique considerations:
- Hidradenitis suppurativa may be the underlying cause if recurrent 4, 5. This requires different management including potential medical therapy and radical surgical excision for severe cases
- Anaerobes are more common in axillary abscesses than other locations, particularly with hidradenitis 4
- Consider metronidazole if foul-smelling discharge suggests anaerobic infection 4
Common Pitfalls to Avoid
- Do not use antibiotics alone without drainage - this will fail 1
- Do not perform needle aspiration - success rates are only 25% overall and <10% with MRSA 1
- Do not routinely pack the wound - this increases pain without benefit 2
- Do not prescribe prophylactic antibiotics - incision and drainage rarely causes bacteremia 1
Follow-up
Ensure patients return if:
- Fever develops or persists
- Erythema spreads beyond 5 cm
- New lesions appear
- The abscess recurs (consider hidradenitis suppurativa or need for decolonization) 1, 6
For recurrent axillary abscesses, consider a 5-day decolonization regimen with intranasal mupirocin twice daily, daily chlorhexidine washes, and decontamination of personal items 1.