What is the treatment for a furuncle (boil)?

Treatment of Furuncles (Boils)

For uncomplicated furuncles, apply warm moist compresses several times daily to promote spontaneous drainage; incision and drainage is reserved for large lesions that fail conservative management, and systemic antibiotics are unnecessary after adequate drainage unless specific high-risk features are present. 1, 2

Initial Management Based on Size

Small Furuncles

• Apply warm, moist compresses to the furuncle several times daily to promote spontaneous drainage, which achieves an 85-90% cure rate whether or not antibiotics are used 1
• The moist heat brings the infection to a head and facilitates natural drainage without surgical intervention 1

Large Furuncles

• Perform incision and drainage for all large furuncles and carbuncles—this is the definitive treatment 2, 3
• Make an incision over the fluctuant area, thoroughly evacuate pus, and probe the cavity to break up loculations 3
• After drainage, cover the wound with a dry dressing rather than packing with gauze—packing is unnecessary and adds pain without improving outcomes 2, 3

Antibiotic Indications

Systemic antibiotics are NOT routinely needed for simple furuncles after adequate drainage 2, 3

Prescribe antibiotics ONLY when any of these conditions exist:

• Fever or systemic inflammatory response syndrome (SIRS) 1, 2, 3
• Extensive surrounding cellulitis 1, 2, 3
• Multiple lesions 1, 2, 3
• Markedly impaired host defenses (immunocompromised status, diabetes) 2, 3

Antibiotic Selection When Indicated

• Use MRSA-active antibiotics given high MRSA prevalence in community-acquired skin infections 2
• First-line options: trimethoprim-sulfamethoxazole, doxycycline, or clindamycin 2, 3
• For children requiring antibiotics: Clindamycin 10-13 mg/kg/dose IV or PO every 6-8 hours if local clindamycin resistance is low (<10%) 1
• Avoid tetracyclines (including doxycycline) in children under 8 years of age 1
• For methicillin-susceptible S. aureus: oral penicillinase-resistant penicillins or first-generation cephalosporins 3

Management of Recurrent Furuncles

Diagnostic Evaluation

• Culture recurrent abscesses early to identify the causative organism and guide antibiotic selection 2
• Search for local anatomic causes: pilonidal cyst, hidradenitis suppurativa, or retained foreign material 2, 3
• Evaluate for neutrophil disorders ONLY if recurrent abscesses began in early childhood (not needed for adult-onset disease) 2

Decolonization Strategy

Offer decolonization when recurrent SSTI persists despite optimizing wound care and hygiene measures, or when ongoing transmission occurs among household members 2

Decolonization Regimen:

• Intranasal mupirocin 2% ointment twice daily for 5 days (reduces recurrences by ~50%) 1, 2, 3
• Daily chlorhexidine body washes for 5-14 days 1, 2, 3
• Daily decontamination of personal items 2, 3
• Thoroughly launder clothing, towels, and bedding 1, 3
• Use separate towels and washcloths for affected individuals 1, 2

Long-term Antibiotic Suppression

• For persistent recurrent disease after failed decolonization, consider low-dose clindamycin for 3 months 4

Important Caveats

• Screening cultures before decolonization are NOT routinely recommended if at least one prior infection was documented as MRSA 2
• Surveillance cultures after decolonization are NOT routinely recommended in the absence of active infection 2
• Culture is not routinely needed for typical, isolated furuncles, but should be obtained in recurrent cases or treatment failures 3
• Needle aspiration has low success rates and is not recommended 3
• When household transmission is suspected, evaluate all contacts for evidence of S. aureus infection and apply hygiene measures to all household members 2
• Nasal colonization with S. aureus is the primary identifiable predisposing factor for most individuals with recurrent disease 2