What antibiotics are used to treat folliculitis and for what duration?

Treatment of Folliculitis: Antibiotic Selection and Duration

For typical folliculitis, a 5-day course of oral antibiotics active against Staphylococcus aureus is recommended, with doxycycline 100mg twice daily being the first-line treatment. 1

First-Line Treatment Options

Mild to Moderate Folliculitis

• Topical therapy:

  • Mupirocin 2% ointment applied to affected areas three times daily for 5-7 days 2
  • For limited skin lesions only 1
  • Clinical efficacy rates of 71-93% in studies 2

• Oral antibiotics (first-line):

  • Doxycycline: 100mg twice daily for 5 days 1, 3
  • Cephalexin: 500mg four times daily for 5 days 1
  • Clindamycin: 300-450mg four times daily for 5 days 1

Moderate to Severe Folliculitis

• Oral antibiotics:
  • Doxycycline: 100mg twice daily for 5-10 days 1, 3
  • Trimethoprim-sulfamethoxazole (TMP-SMX): For suspected MRSA 1

Treatment Duration

The Infectious Diseases Society of America (IDSA) strongly recommends a 5-day course of antimicrobial therapy for typical cases of folliculitis, with extension if the infection has not improved within this time period (strong recommendation, high-quality evidence) 1.

Special Considerations

MRSA Concerns

• For folliculitis associated with:

  • Penetrating trauma
  • Evidence of MRSA infection elsewhere
  • Nasal colonization with MRSA
  • Injection drug use
  • Purulent drainage
  • Systemic inflammatory response syndrome (SIRS)

  Consider coverage for MRSA with:

  • Oral: TMP-SMX, doxycycline, or clindamycin
  • Intravenous (for severe cases): Vancomycin, daptomycin, linezolid, or telavancin 1

Recurrent Folliculitis

For recurrent folliculitis:

1. Culture the lesions and treat with a 5-10 day course of antibiotics active against the isolated pathogen 1
2. Consider a 5-day decolonization regimen:
   • Intranasal mupirocin twice daily
   • Daily chlorhexidine washes
   • Daily decontamination of personal items (towels, sheets, clothes) 1

Prevention Strategies

• Good personal hygiene
• Daily change of socks and underwear
• Avoid sharing towels or personal care items
• Wear flip-flops in communal showers 1
• For athletes or those in close-contact environments:
  • Regular showering after activities
  • Proper drying between toes and in skin folds
  • Use of foot powder after bathing 1

Treatment Algorithm

1. Assess severity:

   • Mild (few isolated lesions): Consider topical therapy alone
   • Moderate to severe (multiple lesions, systemic symptoms): Oral antibiotics

2. Initial treatment:

   • Mild: Mupirocin 2% ointment three times daily for 5-7 days
   • Moderate to severe: Doxycycline 100mg twice daily for 5 days

3. Reassess after 5 days:

   • If improved: Complete course
   • If not improved: Extend treatment and consider culture

4. For recurrent cases:

   • Obtain culture
   • Implement decolonization protocol
   • Consider longer treatment course (7-10 days)

Common Pitfalls to Avoid

• Treating for too short a duration (less than 5 days)
• Failing to consider MRSA in high-risk patients
• Not addressing underlying predisposing factors (e.g., diabetes, immunosuppression)
• Neglecting decolonization for recurrent cases
• Overusing broad-spectrum antibiotics when narrow-spectrum would suffice

The evidence strongly supports a 5-day course of antibiotics for most cases of folliculitis, with doxycycline being a well-established first-line option due to its efficacy against common causative organisms and anti-inflammatory properties.