Gout: allopurinol hypersensitivity: practice question

A Pharmacology 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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Pharmacology · Gout: allopurinol hypersensitivity

Sample item

A patient of Han Chinese ancestry starts allopurinol and three weeks later develops fever, mucosal ulcers and widespread skin blistering. Which genotype is associated with this reaction?

AHLA-DRB1 shared epitopeBHLA-B*5801CHLA-B*5701DHLA-B*1502

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

The answer and the reasoning

B. HLA-B*5801

HLA-B*5801 predicts severe allopurinol hypersensitivity, including SJS/TEN and DRESS, particularly in Han Chinese, Thai and Korean populations. Risk is higher with renal impairment and high starting doses.

Option by option

A. HLA-DRB1 shared epitope
The shared epitope is associated with rheumatoid arthritis susceptibility.
B. HLA-B*5801 (correct)
Correct. HLA-B*5801 is linked to allopurinol hypersensitivity.
C. HLA-B*5701
HLA-B*5701 relates to abacavir.
D. HLA-B*1502
HLA-B*1502 relates to carbamazepine.

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 Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, HLA-B*5801. HLA-B*5801 predicts severe allopurinol hypersensitivity, including SJS/TEN and DRESS, particularly in Han Chinese, Thai and Korean populations.

Why is "HLA-DRB1 shared epitope" not the answer?

The shared epitope is associated with rheumatoid arthritis susceptibility.

Why is "HLA-B*5701" not the answer?

HLA-B*5701 relates to abacavir.

Why is "HLA-B*1502" not the answer?

HLA-B*1502 relates to carbamazepine.

What concept does this question test?

It tests Gout: allopurinol hypersensitivity in Pharmacology. Risk is higher with renal impairment and high starting doses.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Gout: allopurinol hypersensitivity?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology 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.