A 32-year-old man with lepromatous leprosy on multidrug therapy (MDT) for 3 months presents with acute onset fever, painful nodules on extensor surfaces, and tender nerves. Histology shows neutrophilic infiltration with immune complex deposition. What is the most appropriate immediate next step in management?

Explanation

## Lepra Reaction Type 2 (Erythema Nodosum Leprosum) ### Clinical Recognition **Key Point:** This patient has ENL (Erythema Nodosum Leprosum), a Type III hypersensitivity reaction (immune complex-mediated) occurring in lepromatous and borderline lepromatous leprosy patients, typically 6 months to 2 years after starting MDT. **Clinical Pearl:** The triad of fever, painful nodules (often on extensor surfaces), and neuritis with neutrophilic infiltration and immune complex deposition on histology is pathognomonic for ENL. ### Management Algorithm ```mermaid flowchart TD A[ENL diagnosed]:::outcome --> B{Severity assessment}:::decision B -->|Mild: few lesions, no neuritis| C[Continue MDT + NSAIDs/Aspirin]:::action B -->|Moderate: multiple lesions, mild neuritis| D[Continue MDT + Prednisolone 0.5-1 mg/kg/day]:::action B -->|Severe: extensive lesions, severe neuritis/iritis| E[Continue MDT + Prednisolone 1-2 mg/kg/day ± Thalidomide]:::action C --> F[Monitor clinical response]:::action D --> F E --> F F --> G[Taper steroids over 12-24 weeks]:::action ``` ### Rationale for Correct Answer **High-Yield:** The cardinal rule in ENL management is **CONTINUE MDT while treating the reaction**. Stopping MDT allows bacillary multiplication and worsening of leprosy itself. 1. **Systemic corticosteroids** are the first-line anti-inflammatory agent for moderate-to-severe ENL (this patient has neuritis, placing him in the moderate-severe category). 2. Prednisolone at 0.5–1 mg/kg/day is the standard starting dose; higher doses (1–2 mg/kg/day) are reserved for severe cases with ocular or neurological involvement. 3. Gradual taper over 12–24 weeks prevents rebound reaction. **Key Point:** NSAIDs (aspirin, ibuprofen) are adequate for mild ENL; corticosteroids are mandatory once neuritis or systemic features are present. ### Role of Thalidomide - Reserved for **steroid-dependent or steroid-resistant** ENL (after 2–4 weeks of prednisolone without improvement). - Not first-line; not indicated at presentation. ### Why MDT Continues ENL is a host immune response to dead bacilli, not active infection. Stopping MDT: - Allows viable bacilli to proliferate. - Converts the patient back to a higher bacillary load state. - Worsens long-term prognosis. [cite:Park 26e Ch 6]