A 48-year-old man with cutaneous lichen planus affecting his lower extremities and dorsal hands fails to respond to topical corticosteroids after 6 weeks. What is the preferred first-line systemic treatment?

Explanation

## Systemic Treatment of Refractory Cutaneous Lichen Planus **Key Point:** Oral corticosteroids are the first-line systemic agent for widespread or refractory cutaneous lichen planus, offering rapid anti-inflammatory control with a well-established safety profile in dermatology. ### Indications for Systemic Therapy **High-Yield:** Systemic treatment is considered when: - Extensive cutaneous involvement (>10% body surface area) - Failure of topical corticosteroids after 4–6 weeks - Severe pruritus affecting quality of life - Erosive or hypertrophic variants - Oral or genital involvement with significant symptoms ### Why Oral Prednisolone First-Line? 1. **Rapid onset:** Anti-inflammatory effect within 1–2 weeks 2. **Efficacy:** 60–80% response rate in refractory lichen planus 3. **Predictable pharmacokinetics:** Dose-dependent response 4. **Experience:** Decades of safe use in dermatology 5. **Cost-effective:** Inexpensive and widely available ### Dosing Regimen **Clinical Pearl:** Start with prednisolone 0.5–1 mg/kg/day (typically 30–40 mg/day) for 2–4 weeks, then taper by 5–10 mg every 1–2 weeks. Taper duration should equal or exceed initial treatment duration to prevent rebound flare. ### Systemic Therapy Ladder for Refractory Lichen Planus ```mermaid flowchart TD A[Refractory Cutaneous Lichen Planus]:::outcome --> B[Oral Prednisolone 0.5-1 mg/kg/day]:::action B --> C{Response in 2-4 weeks?}:::decision C -->|Yes| D[Taper over 4-8 weeks]:::action C -->|No/Relapse| E[Consider steroid-sparing agent]:::action E --> F{Intolerance to steroids?}:::decision F -->|Yes| G[Methotrexate or Azathioprine]:::action F -->|No| H[Low-dose prednisolone + methotrexate]:::action G --> I[Monitor CBC, LFTs every 4-6 weeks]:::action H --> I ``` ### Comparison of Systemic Agents | Agent | Onset | Efficacy | Monitoring | Adverse Effects | Role | |-------|-------|----------|-----------|-----------------|------| | **Prednisolone** | 1–2 wks | Excellent | Minimal | Hyperglycemia, insomnia, osteoporosis (long-term) | **First-line** | | Methotrexate | 4–8 wks | Good | CBC, LFTs q4–6 wks | Hepatotoxicity, myelosuppression, teratogenic | Steroid-sparing | | Azathioprine | 4–8 wks | Good | CBC, LFTs q4–6 wks | Myelosuppression, hepatotoxicity | Steroid-sparing | | Cyclosporine | 2–4 wks | Excellent | Renal function, BP | Nephrotoxicity, hypertension, gingival hyperplasia | Severe/refractory only | **Mnemonic:** **PUMA** = **P**rednisolone **U**sed **M**ost **A**lways (first-line systemic therapy) ### Monitoring During Systemic Corticosteroid Therapy **Warning:** Screen for and monitor: - Fasting blood glucose (hyperglycemia risk) - Blood pressure - Bone density (if >3 months of therapy) - Opportunistic infections (especially if dose >20 mg/day) - Gastrointestinal symptoms (PPI prophylaxis if risk factors present) ### Steroid-Sparing Alternatives If prednisolone is contraindicated or patient becomes steroid-dependent, transition to: - **Methotrexate:** 10–15 mg weekly (preferred steroid-sparing agent) - **Azathioprine:** 1–2 mg/kg/day - **Combination:** Low-dose prednisolone + methotrexate (synergistic)