A 35-year-old patient with untreated multibacillary leprosy suddenly develops painful erythematous nodules over the face and limbs with fever, malaise, and tender peripheral nerve thickening. The nodules are not present over anaesthetic patches. What is this reaction called?
- A Type 1 lepra reaction (Reversal reaction)
- B Erythema nodosum leprosum (Type 2 reaction) ✓
- C Lucio's phenomenon
- D Erythema multiforme
Correct answer: B. Erythema nodosum leprosum (Type 2 reaction)
Explanation
Erythema nodosum leprosum (ENL) is a Type 2 lepra reaction occurring in lepromatous (LL) and borderline lepromatous (BL) leprosy due to immune-complex deposition (Type III hypersensitivity). It manifests as tender erythematous nodules on normal-appearing skin, accompanied by systemic features like fever, joint pain, and iridocyclitis. The nodules characteristically spare the existing anaesthetic patches. Type 1 reaction involves upgrading of existing patches, not new nodules.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.