What is the treatment for furuncle (boil) and carbuncle (cluster of boils)?

Treatment for Furuncles and Carbuncles

Incision and drainage is the primary treatment for large furuncles and all carbuncles, with systemic antibiotics only necessary when there is fever, extensive surrounding cellulitis, or other evidence of systemic infection. 1

Understanding Furuncles and Carbuncles

• Furuncles (boils): Infections of hair follicles caused by Staphylococcus aureus that extend through the dermis into subcutaneous tissue, forming small abscesses
• Carbuncles: Coalescent inflammatory masses formed when infection involves several adjacent hair follicles, with pus draining from multiple follicular orifices
  • Most commonly develop on the back of the neck
  • More common in people with diabetes
  • Typically larger and deeper than furuncles 1

Treatment Algorithm

For Small Furuncles:

1. Apply moist heat to promote spontaneous drainage 1
2. No systemic antibiotics needed unless complications present

For Large Furuncles and All Carbuncles:

1. Perform incision and drainage (I&D) - this is the definitive treatment 1

   • Make an incision to access the abscess
   • Thoroughly evacuate all pus
   • Probe the cavity to break up loculations
   • Simply cover the surgical site with a dry dressing (preferred approach)
   • Avoid packing the wound with gauze as it may cause more pain without improving healing 1

2. Gram stain and culture of pus from carbuncles and abscesses are recommended, though treatment without these studies is reasonable in typical cases 1

3. Systemic antibiotics are generally NOT necessary unless:

   • Fever or other evidence of systemic infection is present
   • Extensive surrounding cellulitis exists
   • Patient has systemic inflammatory response syndrome (SIRS)
   • Patient has markedly impaired host defenses
   • Multiple lesions are present
   • Cutaneous gangrene is present 1

4. When antibiotics are indicated:

   • Choose an agent active against Staphylococcus aureus
   • Consider MRSA coverage if the patient has risk factors
   • Options for MRSA include doxycycline, clindamycin, or trimethoprim-sulfamethoxazole 1

Management of Recurrent Furunculosis

For patients with recurrent episodes:

1. Search for local causes such as pilonidal cyst, hidradenitis suppurativa, or foreign material 1

2. Implement decolonization measures:

   • Intranasal mupirocin ointment applied twice daily for 5 days each month (reduces recurrences by ~50%) 1, 2
   • Daily chlorhexidine washes 1
   • Daily decontamination of personal items (towels, sheets, clothes) 1
   • Bathing with antibacterial soaps like chlorhexidine 1
   • Thorough laundering of clothing, towels, and bedding 1
   • Separate use of towels and washcloths 1

3. For persistent recurrences with confirmed susceptible S. aureus:

   • Consider clindamycin 150 mg once daily for 3 months (reduces subsequent infections by ~80%) 1

4. Culture recurrent abscesses and treat with a 5-10 day course of antibiotics active against the isolated pathogen 1

Important Caveats and Pitfalls

1. Avoid needle aspiration as treatment for abscesses, as it has low success rates (25% overall, <10% with MRSA infections) 1

2. Don't delay drainage of large furuncles or carbuncles, as this can lead to extension of infection and systemic complications 3

3. Don't routinely prescribe antibiotics for uncomplicated furuncles and carbuncles after adequate drainage 1

4. Consider evaluation for neutrophil disorders in adult patients if recurrent abscesses began in early childhood 1

5. Don't ignore systemic symptoms (fever, tachycardia, hypotension) as they may indicate more serious infection requiring prompt antibiotic therapy 1

6. Be vigilant with facial furuncles as they can lead to serious complications due to venous drainage patterns in this area 4

By following this treatment approach, most furuncles and carbuncles can be effectively managed with minimal complications, focusing on appropriate surgical drainage and judicious use of antibiotics only when indicated.