What is the recommended dose of doxycycline (Doxycycline) for the treatment of folliculitis?

Doxycycline Dosing for Folliculitis

For extensive folliculitis, the recommended dose is doxycycline 100 mg orally twice daily for 7-14 days, with treatment duration based on clinical response and continued until inflammatory lesions resolve and no new pustules develop. 1

Standard Adult Dosing

• Doxycycline 100 mg orally twice daily is the first-line regimen for adults and children over 100 pounds (45 kg) 1
• An optional loading dose of 200 mg on day 1 (administered as 100 mg every 12 hours), followed by 100 mg daily maintenance, may be used 1
• For genital folliculitis specifically, the same dose of 100 mg twice daily for 7-10 days is recommended, providing dual coverage against Staphylococcus aureus and potential sexually transmitted pathogens 2

Treatment Duration

• The standard course is 7-14 days based on clinical response, as recommended by the American Academy of Dermatology 1
• The Infectious Diseases Society of America supports this 7-14 day duration for most bacterial skin and soft tissue infections, including MRSA-associated folliculitis 1
• Continue treatment until inflammatory lesions resolve and no new pustules develop 1

Pediatric Dosing

• For children ≥8 years and ≤45 kg: 2.2 mg/kg orally every 12 hours (maximum 100 mg per dose) 1
• Doxycycline is contraindicated in children <8 years due to risk of permanent tooth discoloration and effects on bone growth 1
• Short courses (≤5 days) have not shown significant dental staining, but the effect of 7-14 day courses on permanent tooth discoloration remains uncertain 1

Administration Considerations

• Patients may take doxycycline with food to minimize gastrointestinal upset 1
• Avoid dairy products within 2 hours before or after dosing to prevent interference with absorption 1
• The American Academy of Dermatology recommends avoiding monotherapy with doxycycline for acne-related conditions to prevent antibiotic resistance 1

Alternative Regimens

If doxycycline is contraindicated or ineffective:

• Azithromycin 500 mg on day 1, then 250 mg daily for days 2-5 2
• Fluoroquinolones: Levofloxacin 500 mg daily or ofloxacin 300 mg twice daily for 7-10 days (provides broader coverage including enteric organisms) 2

Special Populations

Pregnancy

• Doxycycline is generally contraindicated in pregnancy (Pregnancy Category D) due to effects on fetal teeth and bone development 1
• Use only for life-threatening infections where benefits clearly outweigh risks 1

Immunocompromised Patients

• Patients with HIV or other immunocompromised states should receive the same initial doxycycline regimen 2
• Maintain higher suspicion for atypical organisms, including fungi and mycobacteria, if treatment fails 2

Genital Folliculitis

• Rule out sexually transmitted urethritis or epididymitis by assessing for urethral discharge, dysuria, or testicular/epididymal tenderness, which would require different antibiotic coverage 2
• In patients over 35 years with epididymo-orchitis, avoid doxycycline alone as enteric organisms predominate and require fluoroquinolone coverage 2

Common Adverse Effects to Monitor

• Gastrointestinal effects: nausea, vomiting, diarrhea, and esophagitis are common 1
• Dermatologic effects: photosensitivity reactions and rashes can occur 1

Important Clinical Caveats

• For gram-negative folliculitis (which may develop after long-term tetracycline use in acne patients), isotretinoin 0.5-1 mg/kg daily for 4-5 months is the preferred treatment rather than continuing doxycycline 3
• For laser-induced folliculitis, prophylactic doxycycline with topical steroids may help decrease severity and duration 4
• Assess for deep tissue involvement (fever, severe pain, extensive erythema, systemic symptoms) indicating potential Fournier's gangrene or deep soft tissue infection requiring immediate IV broad-spectrum antibiotics and surgical consultation 2