What are the treatment options for a patient with hidradenitis suppurativa (acne inversa) who is allergic to penicillin (antibiotic)?

Treatment of Hidradenitis Suppurativa in Penicillin-Allergic Patients

For patients with hidradenitis suppurativa who are allergic to penicillin, use oral clindamycin 300 mg twice daily combined with rifampicin 300-600 mg daily for 10-12 weeks as first-line systemic therapy for moderate disease, or oral doxycycline 100 mg once or twice daily for 12 weeks for mild disease. 1, 2

Disease Severity Assessment

• Determine Hurley stage first to guide treatment selection: Stage I (isolated nodules without sinus tracts), Stage II (recurrent nodules with limited sinus tracts and scarring), or Stage III (extensive sinus tracts and scarring) 2
• Assess inflammatory lesion count, pain using Visual Analog Scale, and quality of life using DLQI 2
• Document all affected intertriginous areas (axillae, groin, perianal, inframammary) to determine total disease burden 2

Treatment Algorithm for Penicillin-Allergic Patients

Mild Disease (Hurley Stage I)

• Start with topical clindamycin 1% solution or gel applied twice daily to all affected areas for 12 weeks 1, 2, 3
• Combine with benzoyl peroxide wash or chlorhexidine 4% wash daily to reduce Staphylococcus aureus resistance risk, as topical clindamycin monotherapy significantly increases resistance rates 2, 3
• Add intralesional triamcinolone 10 mg/mL (0.2-2.0 mL) for acutely inflamed nodules, which provides rapid symptom relief within 1 day with significant reductions in erythema, edema, suppuration, and pain 2, 3
• If inadequate response after 12 weeks, escalate to oral doxycycline 100 mg once or twice daily for 12 weeks 1, 2

Moderate Disease (Hurley Stage II)

• First-line: Clindamycin 300 mg orally twice daily PLUS rifampicin 300-600 mg orally once or twice daily for 10-12 weeks 1, 2, 4
• This combination achieves response rates of 71-93% in systematic reviews, far superior to tetracycline monotherapy (30% abscess reduction) 2, 5
• The rationale for combining these drugs is to increase bactericidal action and reduce rifampicin resistance, as rifampicin is highly mutagenic 6, 7
• Alternative if clindamycin-rifampicin unavailable or not tolerated: Doxycycline 100 mg once or twice daily for 12 weeks, though this is less effective for abscesses and deep inflammatory nodules 1, 2
• Do NOT use doxycycline as first-line for Hurley Stage II with abscesses, as it has minimal effect on deep inflammatory lesions 2

Severe or Refractory Disease (Hurley Stage III or Failed Antibiotics)

• Escalate to adalimumab: 160 mg subcutaneous at week 0,80 mg at week 2, then 40 mg weekly starting at week 4 1, 2, 8
• Adalimumab is FDA-approved for moderate-to-severe HS in patients ≥12 years old, with HiSCR response rates of 42-59% at week 12 2, 8
• If adalimumab fails after 16 weeks, second-line biologic options include infliximab 5 mg/kg at weeks 0,2,6, then every 2 months, secukinumab (response rates 64.5-71.4% in adalimumab-failure patients), or ustekinumab 1, 2

Alternative Antibiotic Regimens (Penicillin-Free)

• Clindamycin monotherapy 300 mg twice daily for 12 weeks may be considered as an alternative to clindamycin-rifampicin combination, with 61.76% achieving HiSCR in one study, though combination therapy remains superior 9
• Triple therapy: Rifampin 10 mg/kg once daily + moxifloxacin 400 mg daily + metronidazole 500 mg three times daily for 6 weeks, then continue rifampin and moxifloxacin if improving, achieving remission in 100% Hurley Stage 1,80% Hurley Stage 2, and 16.7% Hurley Stage 3 6
• Dapsone 50 mg daily titrating up to 200 mg daily can be considered for patients unresponsive to adalimumab 2

Treatment Monitoring and Duration

• Reassess at 12 weeks using HiSCR (≥50% reduction in abscess/nodule count with no increase in abscesses or draining fistulas), pain VAS score, inflammatory lesion count, and DLQI 2, 4
• Consider treatment break after antibiotic courses to assess need for ongoing therapy and limit antimicrobial resistance 2, 4
• If no clinical response after 12 weeks of clindamycin-rifampicin, escalate to triple therapy or adalimumab 2, 4
• Do not continue doxycycline beyond 4 months without reassessment, as prolonged use increases antimicrobial resistance risk 2

Critical Pitfalls to Avoid

• Do NOT use penicillin-based antibiotics (amoxicillin, amoxicillin-clavulanate) in penicillin-allergic patients [@General Medicine Knowledge]
• Do NOT use topical clindamycin alone for Hurley Stage II, as it only reduces superficial pustules, not inflammatory nodules or abscesses 2
• Ensure rifampicin dose is 300-600 mg daily (not lower doses), and clindamycin must be 300 mg twice daily for systemic effect [@3@]
• Avoid long-term antibiotics without treatment breaks to reduce antimicrobial resistance risk 2, 4
• Be aware that bacterial cultures show high resistance rates to clindamycin (65.7%), rifampicin (69.3%), and tetracycline (84.7%), though clinical efficacy often exceeds in vitro sensitivity [@10@]

Adjunctive Measures (Always Implement)

• Smoking cessation referral, as tobacco use is associated with worse outcomes and higher AISI scores [2, @8@]
• Weight management referral if BMI elevated, as high BMI predicts poor response to antibiotics [@2@, 7]
• Pain management with NSAIDs for symptomatic relief [@2@]
• Appropriate wound dressings for draining lesions [2, @3@]
• Screen for depression/anxiety and cardiovascular risk factors (BP, lipids, HbA1c), as HS patients have increased cardiovascular mortality [@2@, 4]

Surgical Considerations

• Radical surgical excision should be considered for extensive disease with sinus tracts and scarring that fails medical management [@1@, 2]
• Deroofing for recurrent nodules and tunnels [@2