A patient with borderline tuberculoid leprosy, four weeks into MDT, develops sudden enlargement and erythema of existing patches with severe pain and swelling along the ulnar nerve of the affected arm. There is no fever, no crops of new nodules and no systemic upset. The immediate drug of choice is:

• A Thalidomide
• B Clofazimine 300 mg daily
• C Prednisolone, tapered over several weeks ✓
• D Stop all anti-leprosy drugs permanently

Explanation

This is a type 1 (reversal) reaction, a delayed hypersensitivity reaction against M. leprae antigens presenting as inflammation of existing lesions with neuritis and risk of irreversible motor loss. Corticosteroids (prednisolone, tapered over roughly 12 weeks) are the mainstay, and MDT is continued. Thalidomide is the preferred agent for type 2 erythema nodosum leprosum, which features fever, crops of tender nodules and systemic symptoms, and it is ineffective for reversal reactions.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.