A 48-year-old man with a 6-month history of lichen planus presents with painful oral erosions affecting his palate and gingiva, along with cutaneous lesions on his forearms. He reports that his symptoms worsen with spicy food and citrus fruits. His lesions have not responded to topical corticosteroids alone. Which of the following is the most appropriate next step in management?

Explanation

## Management of Erosive Lichen Planus ### Treatment Hierarchy **Key Point:** Erosive oral lichen planus that fails topical corticosteroid therapy requires systemic corticosteroids to achieve disease control and prevent permanent scarring. ### Rationale for Systemic Corticosteroids The patient has: - **Erosive oral disease** (palate and gingiva involvement) - **Failure of topical therapy** after 6 months - **Functional impairment** (pain with eating) - **Risk of progression** to oral cancer (malignant transformation rate ~1–5% in erosive oral lichen planus) **High-Yield:** Erosive oral lichen planus is considered a potentially malignant disorder and requires more aggressive treatment than non-erosive cutaneous disease. ### Treatment Algorithm ```mermaid flowchart TD A[Lichen Planus Diagnosis]:::outcome --> B{Erosive Oral Disease?}:::decision B -->|No| C[Topical Corticosteroids]:::action B -->|Yes| D[Topical + Systemic Corticosteroids]:::action C --> E{Response in 4-6 weeks?}:::decision D --> F{Response in 4-6 weeks?}:::decision E -->|Yes| G[Continue Topical]:::action E -->|No| H[Add Systemic Corticosteroids]:::action F -->|Yes| I[Taper Systemic, Continue Topical]:::action F -->|No| J[Add Steroid-Sparing Agent]:::action J --> K[Retinoids, Cyclosporine, or Azathioprine]:::action ``` ### Recommended Regimen | Component | Recommendation | |-----------|----------------| | **Topical** | Triamcinolone 0.1% paste or fluocinonide gel TDS | | **Systemic** | Prednisolone 0.5–1 mg/kg/day, taper over 8–12 weeks | | **Adjunct** | Topical anesthetic (benzocaine) for pain relief | | **Monitoring** | Clinical response at 4–6 weeks; reassess for tapering | **Clinical Pearl:** Combination therapy (topical + systemic) is superior to monotherapy in erosive oral lichen planus. Systemic corticosteroids should be tapered gradually to prevent rebound flare. ### Steroid-Sparing Alternatives (if needed) If systemic corticosteroids are contraindicated or patient is steroid-dependent: - **Retinoids** (acitretin 25–50 mg/day) - **Cyclosporine** (topical or systemic) - **Azathioprine** (1–2 mg/kg/day) - **Mycophenolate mofetil** **Warning:** Topical calcineurin inhibitors alone are insufficient for erosive disease; they are reserved for non-erosive cutaneous lichen planus or as adjuncts. ### Monitoring for Malignant Transformation **Key Point:** Patients with erosive oral lichen planus require: - Regular clinical examination every 3–6 months - Biopsy of any suspicious lesions (induration, ulceration, color change) - Patient education on oral hygiene and avoidance of irritants (spicy foods, tobacco, alcohol) [cite:Robbins and Cotran 10e Ch 25; Dermatology Textbook of Freedberg et al. 2e]