Treatment of Boils (Furuncles) in Adults
For uncomplicated boils in adults, incision and drainage is the primary treatment, and antibiotics are NOT routinely required unless specific high-risk features are present. 1
Primary Treatment Approach
Incision and Drainage Alone
- Incision and drainage (I&D) is the definitive treatment for boils and should be performed when feasible. 1, 2
- For simple, uncomplicated boils after I&D, antibiotics do not improve healing outcomes and are not routinely recommended. 2
- Wounds larger than 5 cm may benefit from packing to reduce recurrence. 2
When Antibiotics ARE Indicated
Antibiotics should be added to I&D in the following situations: 1, 3
- Systemic signs of infection (fever, tachycardia, hypotension - SIRS criteria)
- Immunocompromised patients
- Failed initial I&D (no improvement after drainage alone)
- Multiple lesions or carbuncles
- Severe or extensive disease
- Inability to adequately drain the abscess
- Associated cellulitis
Antibiotic Selection and Dosing
For Methicillin-Susceptible Staphylococcus aureus (MSSA):
First-line oral options: 1
- Cephalexin 500 mg four times daily (QID) for 7 days
- Dicloxacillin 500 mg QID for 7 days
For Suspected or Confirmed MRSA:
First-line oral options: 1
- Trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily (BID) for 7 days
- Doxycycline 100 mg BID for 7 days
- Clindamycin 300-450 mg QID for 7 days (if local resistance <10-15%)
For Severe Infections Requiring IV Therapy:
MSSA: 1
- Nafcillin 1-2 g every 4 hours IV
- Cefazolin 1 g every 8 hours IV
MRSA: 1
- Vancomycin 30 mg/kg/day in 2 divided doses IV
- Clindamycin 600-900 mg every 8 hours IV
Important Clinical Considerations
Culture Guidance
- Blood cultures and wound cultures are NOT routinely recommended for simple boils. 1
- Cultures should be obtained in immunocompromised patients, those with severe disease, or treatment failures. 1
Duration of Therapy
- Standard duration is 7 days for oral antibiotics when indicated. 1
- Treatment duration depends on clinical response and may be adjusted accordingly. 1
Common Pitfalls
- Avoid prescribing antibiotics for simple boils that can be adequately drained - this contributes to antibiotic resistance without improving outcomes. 2
- Do not assume all S. aureus is MRSA; local epidemiology and patient risk factors should guide empiric choices. 1
- Clindamycin resistance can be inducible in erythromycin-resistant MRSA strains, limiting its reliability. 1
Recurrent Furunculosis Management
For patients with recurrent boils (≥3-4 episodes per year): 4, 5
Decolonization regimen: 1
- Intranasal mupirocin ointment twice daily for 5 days
- Daily chlorhexidine body washes for 5-14 days
- Daily decontamination of personal items (towels, sheets, clothing)
- Consider treating household contacts who are colonized carriers
Suppressive antibiotic therapy options: 4, 6, 5
- Clindamycin 150-300 mg daily for 3 months (most studied)
- Azithromycin 500 mg weekly for 12 weeks (alternative for methicillin-sensitive strains)