Antibiotic of Choice for Hidradenitis Suppurativa
Oral tetracyclines (doxycycline 100 mg or lymecycline 408 mg once or twice daily) are the first-line antibiotic choice for hidradenitis suppurativa, with treatment duration of at least 12 weeks. 1
First-Line Antibiotic Therapy
- Start with oral tetracyclines such as doxycycline 100 mg once or twice daily OR lymecycline 408 mg once or twice daily for a minimum of 12 weeks 1
- Tetracycline 500 mg twice daily is an alternative option for more widespread mild disease, continued for up to 4 months 2
- Consider treatment breaks after completing the course to assess need for ongoing therapy and limit antimicrobial resistance risk 1
The British Association of Dermatologists provides strong recommendations (↑↑) for tetracyclines as initial systemic therapy, reflecting both guideline consensus and clinical experience 1. This approach is appropriate for patients with moderate disease (Hurley Stage I-II) who have not responded adequately to topical therapies 1, 2.
Second-Line Antibiotic Therapy
If tetracyclines fail after 12 weeks, escalate to combination clindamycin 300 mg twice daily PLUS rifampicin 300 mg twice daily for 10-12 weeks. 1
- This combination achieves response rates of 71-93% in systematic reviews, with approximately 80% experiencing substantial improvement and 50% achieving remission 3, 4, 5, 6
- The clindamycin-rifampicin combination is particularly effective for moderate-to-severe HS with abscesses, draining fistulae, and ≥5 inflammatory nodules 3
- Rifampicin dosing can be increased to 300-600 mg daily depending on disease severity 2
Why This Combination Works
The rationale for combining clindamycin with rifampicin includes: (1) enhanced bactericidal action against biofilm-forming bacteria, (2) reduction of rifampicin resistance (as rifampicin is highly mutagenic when used alone), (3) anti-inflammatory effects, and (4) immunomodulatory effects on neutrophils 4. Notably, rifampicin also provides protection against Clostridium difficile infection, which can arise during clindamycin monotherapy 4.
Alternative Antibiotic Monotherapy
- Clindamycin 300 mg twice daily as monotherapy can be considered as a rifampicin-sparing alternative in selected patients, though it is less effective than the combination 7
- This option is appropriate when rifampicin is contraindicated or poorly tolerated 7
Treatment Response Assessment
Reassess at 12 weeks using:
- Visual Analog Scale (VAS) for pain 1, 2
- Inflammatory lesion count 1, 2
- Quality of life measures (DLQI) 1, 2
- Hidradenitis Suppurativa Clinical Response (HiSCR) for patients on biologics 2
Common Pitfalls and Caveats
High BMI and smoking are predictive factors for poor antibiotic response 3. In the clindamycin-rifampicin group, smoking pack-years correlate positively with disease severity scores, while high BMI correlates with poor response in clindamycin monotherapy 3.
Diarrhea is a frequent side effect of the clindamycin-rifampicin combination, occurring in a substantial proportion of patients 6. However, rifampicin's activity against C. difficile provides some protection against antibiotic-associated colitis 4.
Do not continue tetracyclines beyond 4 months without reassessment, as prolonged use increases antimicrobial resistance risk without proven additional benefit 2.
Nonresponders are predominantly patients with severe disease (Hurley Stage III), where surgical intervention may be more appropriate 6.
When Antibiotics Fail
If no response after 12 weeks of clindamycin-rifampicin combination:
- Consider acitretin 0.3-0.5 mg/kg/day (males and non-fertile females only) 1
- Consider dapsone 1
- Offer adalimumab 40 mg weekly for moderate-to-severe HS unresponsive to conventional systemic therapy 1
- Refer to HS surgical multidisciplinary team for extensive excision 1