What is the treatment for carbuncles and furuncles?

Treatment of Carbuncles and Furuncles

The first-line treatment for carbuncles and furuncles is incision and drainage, supplemented with oral antibiotics when there are systemic symptoms, extensive cellulitis, multiple lesions, or in immunocompromised patients. 1

Surgical Management

• Carbuncles: Incision and drainage is mandatory (strong recommendation, high quality evidence) 1

  • Ensure complete evacuation of pus and break up of loculations to prevent treatment failure
  • Avoid needle aspiration (low success rate <25% overall, <10% with MRSA) 1
  • Cover surgical site with a dry dressing after drainage
  • Avoid packing the wound with gauze as it causes more pain without improving healing 1

• Furuncles: Incision and drainage when fluctuant 2

  • Facial furuncles require special attention due to risk of serious complications, including cavernous sinus thrombosis 1

Antibiotic Therapy

Antibiotics are indicated in the following scenarios:

• Systemic symptoms (fever, malaise)
• Extensive surrounding cellulitis
• Multiple lesions
• Immunocompromised patients
• Facial lesions (due to risk of complications)

First-line antibiotic options:

1. Clindamycin: 300-450 mg orally three times a day 1

   • Effective against S. aureus (including MRSA) and streptococci
   • Pediatric dose: 10-13 mg/kg/dose every 6-8 hours, not to exceed 40 mg/kg/day
   • Caution: May cause C. difficile-associated disease more frequently than other oral agents

2. Dicloxacillin: For mild to moderate infections: 125 mg every 6 hours; For severe infections: 250 mg every 6 hours 3

   • Pediatric dose: 12.5 mg/kg/day in equally divided doses every 6 hours for mild to moderate infections; 25 mg/kg/day for severe infections
   • Best absorbed when taken on an empty stomach (1 hour before or 2 hours after meals)
   • Take with at least 4 fluid ounces (120 mL) of water

3. Alternative antibiotics:

   • Trimethoprim-sulfamethoxazole (TMP-SMX): 1-2 double-strength tablets twice a day 1
   • Doxycycline: 100 mg twice a day (not recommended for children under 8 years old) 1
   • Linezolid: 600 mg twice a day (more expensive) 1

Treatment Duration:

• Typically 5-10 days, adjusting according to clinical response 1
• For severe staphylococcal infections, therapy should continue for at least 14 days 3
• Continue treatment for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative 3

Special Considerations

MRSA Coverage

• In areas with high prevalence of community-acquired MRSA, consider empirical coverage with clindamycin, TMP-SMX, or doxycycline 1
• Monitor for inducible resistance to clindamycin in MRSA strains 1

High-Risk Patients

• Diabetic patients: More susceptible to skin infections due to impaired immune function and poor circulation 1
  • Should seek immediate medical care if infection is accompanied by fever, severe pain, or rapid spread, or if they have poorly controlled diabetes

Prevention of Recurrence

• Improve personal hygiene
• Thoroughly launder clothing, towels, and bedding
• Use separate towels and washcloths 1
• For recurrent cases, consider decolonization regimens for S. aureus carriers:
  • Intranasal mupirocin
  • Daily chlorhexidine washes 1
• For diabetic patients, maintain optimal glycemic control 1

Treatment Algorithm

1. Assess the lesion:

   • Single, small furuncle without systemic symptoms → Incision and drainage only
   • Carbuncle, multiple lesions, or systemic symptoms → Incision and drainage + antibiotics

2. Choose antibiotic based on local MRSA prevalence:

   • Low MRSA prevalence: Dicloxacillin
   • High MRSA prevalence: Clindamycin, TMP-SMX, or doxycycline

3. Determine treatment duration:

   • Uncomplicated: 5-10 days
   • Severe infection: At least 14 days

4. Follow-up:

   • Assess response within 48-72 hours
   • If no improvement, consider culture and sensitivity testing to guide antibiotic selection