A 42-year-old woman from Odisha with borderline lepromatous (BL) leprosy has completed 6 months of MDT-MB and shows good clinical response. However, she develops severe erythema nodosum leprosum (ENL) with fever, painful nodules, and neuritis. What is the most appropriate next step in management?

Explanation

## ENL Management During Active MDT **Key Point:** ENL (Type 2 Hypersensitivity Reaction) occurs in **5–10% of BL/LL patients**, typically during or shortly after MDT. **MDT MUST be continued** while treating ENL; discontinuation allows relapse. ### ENL Pathophysiology **High-Yield:** ENL is an **immune complex-mediated (Type III) hypersensitivity reaction**, NOT a drug reaction. It occurs due to: - Antigenic load from dead bacilli - Immune reconstitution - Independent of MDT efficacy ### Management Algorithm for ENL ```mermaid flowchart TD A[ENL Diagnosed]:::outcome --> B{Severity?}:::decision B -->|Mild: nodules only| C[Continue MDT + NSAIDs + Prednisolone 0.5-1 mg/kg]:::action B -->|Moderate: neuritis/iritis| D[Continue MDT + Prednisolone 1-2 mg/kg]:::action B -->|Severe: systemic involvement| E[Continue MDT + High-dose Prednisolone 2-3 mg/kg]:::action C --> F{Response in 2-4 weeks?}:::decision D --> F E --> F F -->|Yes| G[Taper corticosteroids over 3-6 months]:::action F -->|No| H[Add Thalidomide 100-300 mg/day]:::action H --> I[Continue MDT throughout]:::action ``` ### Corticosteroid Dosing in ENL | Severity | Prednisolone Dose | Duration | |----------|-------------------|----------| | Mild | 0.5–1 mg/kg/day | 4–6 weeks, then taper | | Moderate | 1–2 mg/kg/day | 6–8 weeks, then taper | | Severe | 2–3 mg/kg/day | 8–12 weeks, then taper | **Clinical Pearl:** Thalidomide (100–300 mg/day) is reserved for: - Corticosteroid-dependent ENL - Severe/recurrent ENL - Contraindicated in pregnancy (teratogenic) **Warning:** ~~Discontinuing MDT~~ is a common mistake. ENL is NOT an indication to stop MDT; it is a complication that develops *during* effective treatment. ### Why Continue MDT During ENL? 1. **Bacillary load still high** in BL/LL patients; stopping MDT allows relapse 2. **ENL is self-limited** if immune reconstitution continues 3. **WHO guidelines explicitly recommend** continuing MDT + immunosuppression in parallel 4. **Relapse risk** increases dramatically if MDT is interrupted **Mnemonic:** **CENT = Continue MDT, Eliminate immune reaction with corticosteroids, Neuritis management, Thalidomide if severe**