Is doxycycline appropriate for treating mild‑to‑moderate hidradenitis suppurativa in an adult patient without contraindications (no tetracycline allergy, not pregnant or lactating, no severe liver or kidney disease)?

Doxycycline for Hidradenitis Suppurativa

Yes, doxycycline 100 mg once or twice daily for 12 weeks is an appropriate first-line oral antibiotic for mild-to-moderate hidradenitis suppurativa (Hurley Stage I or mild Stage II without deep abscesses), though it is significantly less effective than the clindamycin-rifampicin combination for moderate disease with inflammatory nodules or abscesses. 1, 2

Treatment Algorithm by Disease Severity

For Mild Disease (Hurley Stage I: Isolated Nodules Without Sinus Tracts)

• Start with topical clindamycin 1% solution or gel twice daily for 12 weeks as first-line therapy, combined with benzoyl peroxide wash to reduce Staphylococcus aureus resistance risk. 1, 2, 3
• Escalate to oral doxycycline 100 mg once or twice daily for 12 weeks if topical therapy fails or for more widespread mild disease. 1, 2, 4
• Doxycycline can be extended up to 4 months (16 weeks) for persistent mild disease. 2

For Moderate Disease (Hurley Stage II: Recurrent Nodules with Limited Sinus Tracts)

• Do NOT use doxycycline monotherapy as first-line for Hurley Stage II with abscesses or deep inflammatory nodules—it achieves only ~30% abscess reduction and has minimal effect on deep lesions. 2
• First-line therapy is clindamycin 300 mg twice daily PLUS rifampicin 300-600 mg daily for 10-12 weeks, which achieves response rates of 71-93%, far superior to doxycycline. 1, 2, 5
• Doxycycline may be used for mild Hurley Stage II disease without deep inflammatory lesions or abscesses. 2

For Severe Disease (Hurley Stage III: Multiple Sinus Tracts and Scarring)

• Doxycycline is inadequate; initiate clindamycin-rifampicin while awaiting specialist evaluation or proceed directly to adalimumab (160 mg week 0,80 mg week 2, then 40 mg weekly). 1, 2

Evidence Quality and Limitations

The evidence supporting doxycycline in hidradenitis suppurativa is notably weak. 2

• Only one randomized controlled trial exists comparing tetracycline to topical clindamycin, showing modest 30% abscess reduction with no significant improvement in patient-reported outcomes. 2
• A 2021 prospective study of 108 patients found that tetracycline 500 mg twice daily provided greater HSS improvement than doxycycline 100 mg twice daily, though all three tetracyclines (tetracycline, doxycycline, lymecycline) showed efficacy. 4
• A 2022 randomized trial demonstrated that subantimicrobial modified-release doxycycline 40 mg daily achieved comparable HiSCR response (64%) to regular-release doxycycline 100 mg twice daily (60%) at 12 weeks, suggesting anti-inflammatory rather than antimicrobial mechanisms. 6
• Real-world data from a Greek tertiary hospital showed doxycycline 100 mg twice daily for 1-2 weeks then once daily for up to 12 weeks was the most popular treatment choice (66% of patients), reflecting its widespread use despite limited evidence. 7

Treatment Duration and Monitoring

• Treat for 12 weeks initially, then reassess using pain visual analogue scale (VAS), inflammatory lesion count (nodules + abscesses), number of flares in the preceding month, and Dermatology Life Quality Index (DLQI). 1, 2
• HiSCR (Hidradenitis Suppurativa Clinical Response) is the gold standard outcome measure: ≥50% reduction in abscess/nodule count with no increase in abscesses or draining fistulas. 2
• After completing the 12-week course, institute a treatment break to assess need for ongoing therapy and limit antimicrobial resistance risk. 1, 2, 5

When to Escalate Treatment

• If no clinical response after 12 weeks of doxycycline, escalate to clindamycin 300 mg twice daily plus rifampicin 300-600 mg daily for 10-12 weeks. 1, 2
• If clindamycin-rifampicin fails after 12 weeks, escalate to adalimumab or refer to dermatology for consideration of biologics (secukinumab, ustekinumab, infliximab) or surgical intervention. 1, 2

Critical Pitfalls to Avoid

• Do not use doxycycline as first-line for Hurley Stage II with deep inflammatory lesions or abscesses—it has minimal effect on these lesions. 2
• Do not continue doxycycline beyond 4 months without reassessment—prolonged use increases antimicrobial resistance risk without proven additional benefit. 2
• Do not use doxycycline monotherapy for moderate-to-severe disease—the clindamycin-rifampicin combination is vastly superior (71-93% vs. 30% response). 2

Mandatory Adjunctive Measures (All Patients)

• Smoking cessation referral—70-75% of HS patients are smokers; tobacco worsens outcomes. 1, 2
• Weight management referral if BMI elevated—obesity prevalence exceeds 75% in HS patients. 1, 2
• Pain management with NSAIDs for symptomatic relief. 1, 2
• Appropriate wound dressings for draining lesions. 1, 2
• Screen for depression/anxiety and cardiovascular risk factors (blood pressure, lipids, HbA1c)—these comorbidities are highly prevalent in HS. 1, 2

Special Population Considerations

• Pediatric patients ≥8 years old: Doxycycline 100 mg once or twice daily is appropriate. 2
• Breastfeeding patients: Limit doxycycline to ≤3 weeks without repeating courses; consider amoxicillin/clavulanic acid, erythromycin, azithromycin, or metronidazole as alternatives. 2
• HIV-positive patients: Doxycycline offers added prophylactic benefit against bacterial sexually transmitted infections. 2, 5
• Pregnant patients: Doxycycline is contraindicated; use oral clindamycin with caution. 5