What antibiotics are used to treat bacterial folliculitis?

Antibiotics for Bacterial Folliculitis

For simple bacterial folliculitis, topical benzoyl peroxide is the first-line treatment, reserving topical antibiotics (mupirocin or clindamycin) for cases requiring antimicrobial therapy, and oral antibiotics (cephalexin or dicloxacillin) only for treatment-resistant cases. 1

Treatment Algorithm by Severity

Mild, Localized Folliculitis

• Start with topical benzoyl peroxide as a non-antibiotic first-line option, which is effective and avoids antimicrobial resistance 1
• If topical antimicrobial therapy is needed, use topical mupirocin or clindamycin 1
• Simple folliculitis is typically self-limited and may resolve without antibiotics 1

Treatment-Resistant or Extensive Folliculitis

• Oral cephalexin or dicloxacillin are appropriate options when topical therapy fails 1
• These beta-lactam antibiotics provide coverage against Staphylococcus aureus, the primary causative organism 1
• Treatment duration typically ranges from 7-14 days, though specific duration should be guided by clinical response 2

Chronic or Recurrent Folliculitis

• Consider isotretinoin (0.5-1 mg/kg daily for 4-5 months) for gram-negative folliculitis, particularly in patients who have failed prolonged antibiotic therapy 3
• Gram-negative folliculitis should be suspected in patients who have not improved after 3-6 months of tetracycline treatment 3
• Isotretinoin has shown superior long-term remission rates (90%) compared to antibiotics in certain folliculitis variants 4

MRSA Considerations

MRSA coverage should be considered for infections that have not improved with standard beta-lactam treatment 1. However, MRSA is an unusual cause of typical folliculitis without purulent drainage 2.

• For suspected MRSA folliculitis, oral options include doxycycline, clindamycin, or trimethoprim-sulfamethoxazole (SMX-TMP) 2
• If both streptococcal and MRSA coverage is desired, use clindamycin alone or combine SMX-TMP or doxycycline with a beta-lactam (such as cephalexin) 2
• The activity of doxycycline and SMX-TMP against beta-hemolytic streptococci is uncertain, so beta-lactam monotherapy is preferred when there is no purulent drainage 2

Important Caveats

Culture and sensitivity testing is rarely performed but should be considered in recurrent cases to guide appropriate antibiotic selection 1, 5. The occurrence of gram-negative folliculitis is generally underestimated because correct sampling and bacteriology are infrequently performed 3.

Avoid prolonged antibiotic courses as they can lead to bacterial interference and gram-negative folliculitis, particularly with organisms like E. coli, Pseudomonas aeruginosa, and Proteus mirabilis 3.

Incision and drainage is the primary treatment for follicular abscesses (furuncles and carbuncles), with oral antibiotics reserved only for patients with severe immunocompromise or systemic signs of infection 1.