A 28-year-old woman with borderline tuberculoid leprosy (BT) on MDT for 3 months presents with acute swelling and inflammation of her existing skin lesions, painful nodules, and severe neuritis of the right ulnar nerve with loss of sensation in the 4th and 5th fingers. She has no fever or systemic symptoms. Bacillary index remains moderately high. What is the most appropriate management?

Explanation

## Clinical Diagnosis: Type 1 Lepra Reaction (Reversal Reaction) **Key Point:** Type 1 lepra reaction presents with acute inflammation of existing lesions and neuritis in tuberculoid-spectrum patients (BT, BL) during MDT. Management is **corticosteroids + continue MDT**, with consideration for nerve decompression if neuritis is severe and unresponsive. ## Type 1 vs Type 2 Lepra Reactions | Feature | Type 1 (Reversal) | Type 2 (ENL) | |---------|-------------------|---------------| | **Spectrum** | BT, BL (tuberculoid) | LL, BL (lepromatous) | | **Timing** | Before/during/early after MDT | During/after MDT (6 mo–2 yrs) | | **Pathophysiology** | Cell-mediated (Type IV) | Immune complex (Type III) | | **Fever/systemic** | Absent | Present | | **Neuritis** | Common, severe | Uncommon | | **Bacillary index** | High or moderate | Decreasing | | **Management** | Corticosteroids + MDT | Thalidomide/corticosteroids + MDT | **High-Yield:** Type 1 reversal reaction is characterized by **neuritis** (often severe) with minimal systemic symptoms—a key distinguishing feature from Type 2 ENL. ## Pathophysiology Type 1 is a **cell-mediated immune response** (Type IV hypersensitivity): 1. Delayed hypersensitivity to *M. leprae* antigens 2. Occurs when immune system shifts toward Th1 response 3. Inflammation of skin lesions and nerves (high antigen concentration) 4. Can occur at any stage of MDT ## Management Protocol ```mermaid flowchart TD A[Type 1 Lepra Reaction diagnosed]:::outcome --> B{Neuritis present?}:::decision B -->|Yes| C[Start oral corticosteroids<br/>0.5-1 mg/kg/day prednisone]:::action B -->|No| D[Mild-moderate inflammation<br/>Corticosteroids as needed]:::action C --> E{Nerve function improving<br/>at 4 weeks?}:::decision E -->|Yes| F[Taper steroids over 12 weeks<br/>Continue MDT]:::action E -->|No| G[Consider nerve decompression<br/>if severe deficit]:::urgent D --> H[Continue MDT throughout]:::action F --> H G --> H ``` **Key Point:** **Never stop MDT** during lepra reactions. Continue the full course while treating the reaction. **Clinical Pearl:** Nerve decompression is indicated if: - Severe neuritis with rapid motor loss - No improvement after 4 weeks of high-dose corticosteroids - Risk of permanent nerve damage **Mnemonic: NEURITIS in Type 1** — **N**euritis is prominent, **E**xisting lesions inflame, **U**sually BT/BL, **R**eversal reaction, **I**mmune cell-mediated, **T**uberculoid spectrum, **I**nclude steroids, **S**tay on MDT. [cite:Park 26e Ch 12; Harrison 21e Ch 189]