Treatment of Pemphigus
First-line treatment for pemphigus should combine oral corticosteroids (prednisolone 1 mg/kg/day in most cases, 0.5-1 mg/kg/day in milder disease) with an adjuvant immunosuppressant from the outset—specifically azathioprine, mycophenolate mofetil, or rituximab. 1
First-Line Therapy Algorithm
Corticosteroids (Backbone of Treatment)
- Start with oral prednisolone 1 mg/kg/day for moderate-to-severe disease
- Use 0.5-1 mg/kg/day for milder presentations
- If no response within 5-7 days, increase dose by 50-100% increments
- Consider pulsed IV methylprednisolone (10-20 mg/kg or 250-1000 mg) if oral doses exceed 1 mg/kg/day or for severe initial presentation
- Clinical improvement typically occurs within days; cessation of blistering takes 2-3 weeks on average, with full healing in 3-8 weeks 1
Critical caveat: Historical high-dose regimens (120-400 mg/day prednisolone) caused excessive mortality—up to 77% of deaths were corticosteroid-related. The moderate-dose approach (1 mg/kg/day) is safer without compromising efficacy 1.
Adjuvant Immunosuppressants (Mandatory, Not Optional)
Combine corticosteroids with one of these from treatment initiation:
- Azathioprine 2-3 mg/kg/day (check TPMT levels first)
- Mycophenolate mofetil 2-3 g/day
- Rituximab (rheumatoid arthritis protocol: 2 × 1 g infusions, 2 weeks apart)
The evidence strongly favors rituximab: A landmark 2017 RCT demonstrated rituximab combined with short-term prednisolone achieved 89% complete remission off all treatment at 2 years, compared to only 28% with prednisolone alone 1. This represents the most compelling evidence for superior long-term outcomes prioritizing mortality and quality of life.
Important timing note: Adjuvant drugs are more critical for remission maintenance than induction due to delayed onset of action. They collectively decrease relapse risk by 29% 1.
Tapering Strategy
- Begin tapering once remission is induced and maintained (no new blisters, healing of majority of lesions)
- Aim to reduce prednisolone to ≤10 mg daily
- Do not taper prematurely: 47% of successfully treated patients relapsed when treatment stopped after only 1 year 1
- Assess osteoporosis risk immediately upon starting corticosteroids 1
Second-Line Therapy
Switch to an alternate corticosteroid-sparing agent if treatment failure occurs with first-line adjuvant:
- Try a different agent among azathioprine, mycophenolate mofetil, or rituximab
- Consider mycophenolic acid 720-1080 mg twice daily if GI symptoms from mycophenolate mofetil 1
Treatment failure is defined as: Continued disease activity or failure to heal despite 3 weeks of prednisolone 1.5 mg/kg/day, or 12 weeks of adequate doses of adjuvant drugs 1.
Third-Line Therapy
Based on multidisciplinary assessment, consider:
- Cyclophosphamide
- Intravenous immunoglobulin (IVIG)
- Immunoadsorption
- Methotrexate
- Plasmapheresis/plasma exchange 1
Long-Term Outcomes and Withdrawal
Treatment withdrawal is realistic: Complete remission off-therapy rates are 38% at 3 years, 50% at 5 years, and 75% at 10 years from diagnosis 1. However, 59% of patients achieved off-treatment status after a mean of 3 years, and this outcome was not associated with initial disease severity 1.
Regulatory Context
Important limitation: While rituximab shows superior efficacy, it is currently approved by NHS England only as third-line treatment for pemphigus. Many regulatory authorities have not yet approved rituximab as first-line treatment 1. However, the evidence clearly supports its use when accessible, particularly given the dramatic improvement in complete remission rates and reduction in long-term corticosteroid exposure.
Recent observational data confirms corticosteroids remain the most prescribed treatment in real-world practice, with rituximab increasingly used (21 patients in one 10-year cohort) 2. The treatment landscape is evolving toward earlier rituximab use as regulatory approvals expand 3, 4, 5.