Antibiotic Treatment for Folliculitis
For uncomplicated bacterial folliculitis, topical mupirocin 2% ointment applied three times daily is first-line therapy for minor infections, while oral antibiotics are reserved for extensive or recurrent disease. 1
Initial Assessment and Pathogen Identification
- Folliculitis is most commonly caused by Staphylococcus aureus (both methicillin-susceptible and methicillin-resistant strains) and occasionally by Streptococcus pyogenes. 2, 3
- Obtain cultures from purulent drainage before starting antibiotics to confirm the pathogen and guide definitive therapy, particularly when MRSA is suspected. 4
- Pseudomonas aeruginosa ("hot tub folliculitis") should be considered in patients with recent hot tub or swimming pool exposure, though this typically resolves without antibiotics. 3
Topical Therapy for Localized Folliculitis
- Mupirocin 2% ointment applied three times daily for 5–7 days is effective for minor, localized folliculitis caused by MSSA. 1, 4
- Topical fusidic acid is widely used as adjuvant treatment for staphylococcal folliculitis, though evidence for its use as monotherapy is limited. 5
Oral Antibiotics for Extensive or Recurrent Folliculitis
Methicillin-Susceptible Staphylococcus aureus (MSSA)
- Dicloxacillin 250–500 mg orally every 6 hours for 5–10 days provides excellent coverage for MSSA folliculitis. 2, 3, 6
- Cephalexin 500 mg orally every 6 hours for 5–10 days is an equally effective alternative with comparable streptococcal and MSSA activity. 2, 3, 6
- Clindamycin 300–450 mg orally every 6–8 hours for 5–10 days covers both MSSA and streptococci, but should only be used if local MRSA clindamycin resistance rates are <10%. 2, 3, 6
- Erythromycin 250–500 mg orally four times daily is an option for penicillin-allergic patients, though resistance rates are increasing. 2, 3
Community-Associated MRSA (CA-MRSA)
- Trimethoprim-sulfamethoxazole (TMP-SMX) 1–2 double-strength tablets (160–320/800–1600 mg) orally twice daily for 5–10 days is first-line for CA-MRSA folliculitis. 4, 2, 6
- Doxycycline 100 mg orally twice daily for 5–10 days is an effective alternative, but is contraindicated in children <8 years and pregnant women. 4, 2, 6
- Minocycline 100 mg orally twice daily for 5–10 days has superior clinical effectiveness compared to doxycycline for MRSA infections. 2, 6
- Clindamycin 300–450 mg orally every 6–8 hours for 5–10 days provides single-agent coverage for both MRSA and streptococci, but use only if local clindamycin resistance is <10%. 4, 2, 6
- Linezolid 600 mg orally twice daily is reserved for complicated cases due to high cost. 2, 6
Pseudomonas aeruginosa (Hot Tub Folliculitis)
- Most cases of Pseudomonas folliculitis resolve spontaneously without antibiotics within 7–10 days. 3
- For severe or persistent cases, ciprofloxacin 500–750 mg orally twice daily for 7–10 days provides targeted Pseudomonas coverage. 3
Oral Fusidic Acid for Recalcitrant Folliculitis
- Oral fusidic acid 500 mg three times daily for 2–3 weeks has shown efficacy in treating recurrent or severe folliculitis, particularly folliculitis decalvans, though data are limited. 5
- Fusidic acid is highly bioavailable orally, has a long plasma half-life, and maintains low resistance rates despite years of clinical use. 5
- Maintenance therapy with zinc sulfate may reduce recurrence after completing fusidic acid treatment. 5
Treatment Duration
- For uncomplicated folliculitis, 5–10 days of oral antibiotics is sufficient, individualized based on clinical response. 4, 2
- Extend therapy to 7–14 days only for complicated infections involving deeper tissues, multiple sites, or systemic toxicity. 4
Adjunctive Measures
- Keep affected areas clean and dry; avoid sharing personal items such as towels, razors, or clothing. 4
- For recurrent folliculitis, consider decolonization with mupirocin (nasal) and chlorhexidine (body) to eradicate S. aureus carriage. 4
- Address predisposing factors such as shaving trauma, occlusive clothing, or underlying skin conditions (e.g., eczema). 4
Common Pitfalls to Avoid
- Do not use beta-lactam antibiotics (e.g., amoxicillin, cephalexin, dicloxacillin) for suspected MRSA folliculitis, as they lack activity against MRSA due to mecA-mediated resistance. 4, 6
- Do not use TMP-SMX or doxycycline as monotherapy for typical folliculitis if streptococcal co-infection is suspected, as they lack reliable activity against beta-hemolytic streptococci. 4, 2
- Avoid prolonged or repeated courses of antibiotics without addressing underlying predisposing factors, as this promotes resistance and recurrence. 4
When to Escalate to Intravenous Therapy
- Hospitalization with IV antibiotics is necessary for patients with systemic toxicity (fever, tachycardia, hypotension), rapidly progressive infection, or failure of outpatient therapy. 4
- Vancomycin 15–20 mg/kg IV every 8–12 hours is first-line for severe MRSA folliculitis requiring hospitalization. 4, 6
- Alternatives include linezolid 600 mg IV twice daily or daptomycin 4–6 mg/kg IV once daily. 4, 6