Post-Excision Antibiotic Therapy for Hidradenitis Suppurativa
For patients with hidradenitis suppurativa after excision surgery, oral clindamycin 300 mg twice daily combined with rifampicin 300-600 mg daily for 10-12 weeks is the recommended post-operative antibiotic regimen to prevent recurrence and manage residual disease. 1
Rationale for Combination Therapy
The clindamycin-rifampicin combination achieves response rates of 71-93% in systematic reviews, far superior to monotherapy options. 2, 3, 4 This combination is specifically recommended for moderate-to-severe HS, which characterizes most patients requiring surgical excision. 1
The rationale for combining these two antibiotics is to increase bactericidal action and reduce rifampicin resistance, as rifampicin is highly mutagenic when used alone. 3 The combination therapy dramatically improves disease severity scores (Sartorius score median reduction from 29 to 14.5, p<0.001) and quality of life measures. 4
Specific Dosing Regimen
- Clindamycin: 300 mg orally twice daily 1, 2
- Rifampicin: 300-600 mg orally once daily (or 300 mg twice daily) 1, 2
- Duration: 10-12 weeks 1, 2
The British Association of Dermatologists explicitly recommends this regimen in their management pathway for lack of response to initial therapy and for Hurley stage III disease. 1
Alternative: Clindamycin Monotherapy
If rifampicin is contraindicated or not tolerated, clindamycin monotherapy at 300 mg twice daily for 12 weeks may be considered as an alternative, though it is less effective than combination therapy. 3, 5
Recent evidence shows clindamycin monotherapy achieves Hi-SCR (HS Clinical Response) in 61.76% of patients, with mean HS-PGA scores decreasing from 3.24 to 2.15 (p=0.001). 5 However, multilinear regression models demonstrate significantly higher reduction in disease severity scores with combination therapy (Δ = -13.2 for mSartorius, p=0.058; Δ = -4.91 for AISI, p=0.034). 3
Treatment Monitoring and Breaks
Reassess treatment response at 12 weeks using pain VAS score, inflammatory lesion count, number of flares, and quality of life (DLQI). 1, 2
Consider treatment breaks after completing the 10-12 week course to assess need for ongoing therapy and limit antimicrobial resistance risk. 1 This is particularly important given that clindamycin may increase rates of Staphylococcus aureus resistance. 2
Predictors of Poor Response
High BMI and smoking pack-years are predictive factors of poor antibiotic response. 3 In the clindamycin-rifampicin group, smoking pack-year positively correlates with disease severity (AISI: Spearman's rho = 0.51, p=0.036). 3 In clindamycin monotherapy, BMI positively correlates with disease severity (AISI: 0.47, p=0.041). 3
Therefore, mandatory adjunctive measures include smoking cessation referral and weight management referral to optimize treatment outcomes. 1, 2, 6
Critical Pitfalls to Avoid
Do not use tetracycline or doxycycline monotherapy post-excision, as these have minimal effect on deep inflammatory lesions and abscesses (only 30% abscess reduction), which are characteristic of disease requiring surgical intervention. 2, 7
Do not use topical clindamycin alone post-excision, as it only reduces superficial pustules, not inflammatory nodules or abscesses. 2, 7, 8
Do not use rifampicin as monotherapy due to high mutagenic potential and rapid development of resistance. 3
Avoid long-term continuous antibiotic use without treatment breaks to reduce antimicrobial resistance risk. 1
Adverse Events and Monitoring
Adverse events occur in approximately 6.9-26.42% of patients on clindamycin-based regimens. 4, 5 The most common side effects are gastrointestinal, with higher doses increasing incidence. 9
Monitor for:
- Gastrointestinal side effects (diarrhea, nausea) 9, 4
- Clostridioides difficile infection risk with prolonged use 9
- Hepatotoxicity with rifampicin (monitor liver enzymes if treatment extends beyond 12 weeks) 3
Post-Operative Context
While the guidelines do not specifically address post-excision antibiotic prophylaxis as a distinct entity, the combination therapy is recommended for patients with extensive disease requiring surgical intervention, which inherently includes the post-operative period. 1, 2 The 2019 British Association of Dermatologists guidelines note that surgical interventions should be integrated with medical management, and the clindamycin-rifampicin regimen is positioned as treatment for severe disease that would require surgical referral. 1
When to Escalate Beyond Antibiotics
If no clinical response after 10-12 weeks of clindamycin-rifampicin combination therapy, escalate to biologic therapy with adalimumab (160 mg at week 0,80 mg at week 2, then 40 mg weekly starting week 4). 1, 2, 6 Adalimumab achieves HiSCR response rates of 42-59% at week 12 and is FDA-approved for moderate-to-severe HS in patients ≥12 years old. 2, 6
Consider combining adalimumab with surgery for greater clinical effectiveness than adalimumab monotherapy, particularly for extensive disease with residual sinus tracts post-excision. 2, 6