Leprosy: necrotising erythema nodosum leprosum: practice question

A Dermatology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Dermatology · Leprosy: necrotising erythema nodosum leprosum

Sample item

A lepromatous leprosy patient on multidrug therapy develops fever and tender red nodules over the limbs, some of which turn pustular, ulcerate and form necrotic scars. Which description is most accurate?

AA severe necrotising form of erythema nodosum leprosumBLucio phenomenon of untreated diffuse leprosyCA type 1 reversal reactionDErythema multiforme from dapsone

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. A severe necrotising form of erythema nodosum leprosum

Erythema nodosum leprosum is an immune-complex mediated type 2 reaction, and in severe cases the nodules become pustular, ulcerate and heal with scarring (necrotising ENL). It occurs in lepromatous and borderline lepromatous disease, often during treatment. Lucio phenomenon is a distinct vasculitic process in untreated diffuse lepromatous leprosy.

Option by option

A. A severe necrotising form of erythema nodosum leprosum (correct)
Correct. Ulcerating pustular nodules with fever on treatment represent necrotising ENL.
B. Lucio phenomenon of untreated diffuse leprosy
Lucio phenomenon occurs in untreated diffuse non-nodular leprosy and gives large angular ulcers.
C. A type 1 reversal reaction
Type 1 reactions inflame existing lesions with neuritis, not new tender nodules with fever.
D. Erythema multiforme from dapsone
Erythema multiforme gives target lesions, not tender necrotic nodules.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is A, A severe necrotising form of erythema nodosum leprosum. Erythema nodosum leprosum is an immune-complex mediated type 2 reaction, and in severe cases the nodules become pustular, ulcerate and heal with scarring (necrotising ENL).

Why is "Lucio phenomenon of untreated diffuse leprosy" not the answer?

Lucio phenomenon occurs in untreated diffuse non-nodular leprosy and gives large angular ulcers.

Why is "A type 1 reversal reaction" not the answer?

Type 1 reactions inflame existing lesions with neuritis, not new tender nodules with fever.

Why is "Erythema multiforme from dapsone" not the answer?

Erythema multiforme gives target lesions, not tender necrotic nodules.

What concept does this question test?

It tests Leprosy: necrotising erythema nodosum leprosum in Dermatology. It occurs in lepromatous and borderline lepromatous disease, often during treatment. Lucio phenomenon is a distinct vasculitic process in untreated diffuse lepromatous leprosy.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Leprosy: necrotising erythema nodosum leprosum?

Learn each condition by its primary lesion, site and signature sign. Then use the flashcards and the other Dermatology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.