A 35-year-old man from rural Maharashtra presents with hypopigmented macules on his face and trunk with loss of sensation over the lesions. Slit-skin smear is positive for acid-fast bacilli (AFB). He is diagnosed with borderline tuberculoid leprosy. He is started on multidrug therapy (MDT). After 2 weeks of treatment, he develops acute painful nodules, fever, and worsening of existing skin lesions. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis: Type 2 Lepra Reaction (Erythema Nodosum Leprosum) ### Presentation Recognition The patient has developed acute inflammatory nodules, fever, and worsening skin lesions within 2 weeks of starting MDT. This is a classic presentation of **Type 2 lepra reaction (ENL)**, an immune complex-mediated reaction that occurs in lepromatous and borderline lepromatous leprosy during treatment. **Key Point:** Type 2 reactions (ENL) are immune complex-mediated and occur in LL and BL leprosy, typically 1–2 weeks after starting MDT or even years into treatment. ### Management Algorithm ```mermaid flowchart TD A[Type 2 Lepra Reaction Suspected]:::outcome --> B{Severity?}:::decision B -->|Mild/Moderate| C[Continue MDT + Corticosteroids]:::action B -->|Severe/Systemic| D[Continue MDT + High-dose Corticosteroids]:::action C --> E[Prednisolone 0.5-1 mg/kg/day, taper over weeks]:::action D --> E E --> F[Monitor response, adjust dose]:::action F --> G[Thalidomide if recurrent/steroid-dependent]:::action ``` ### Correct Management **Continue MDT** — Antileprotic drugs must NOT be stopped; they are essential to control the infection and prevent further bacillary multiplication. **Add Systemic Corticosteroids** — Prednisolone 40–60 mg/day (or 0.5–1 mg/kg/day) is the first-line anti-inflammatory agent. Gradual taper over 4–12 weeks prevents rebound. **High-Yield:** Thalidomide is reserved for recurrent or steroid-dependent ENL, not first-line. NSAIDs alone are insufficient for moderate–severe reactions. **Clinical Pearl:** ENL is a sign of immune reconstitution and bacillary death — it indicates the immune system is responding to antigen release. Continuing MDT while suppressing inflammation is the cornerstone. ### Differential: Type 1 Reaction (Reversal Reaction) Type 1 reactions are cell-mediated, occur in BT, BL, and BB leprosy, and also respond to corticosteroids but are triggered by immune shifts rather than immune complex deposition. Both are managed with corticosteroids while continuing MDT. [cite:Park 26e Ch 7]