Acne: isotretinoin: 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 · Acne: isotretinoin

Sample item

A man with nodulocystic acne unresponsive to antibiotics is started on oral isotretinoin. Which mechanism and caution are correct?

AIt reduces sebaceous gland size and sebum, and is strongly teratogenicBIt blocks androgen receptors, and is safe in pregnancyCIt kills Cutibacterium only, and is safe in pregnancyDIt is an antifungal that lowers cholesterol

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

The answer and the reasoning

A. It reduces sebaceous gland size and sebum, and is strongly teratogenic

Isotretinoin shrinks sebaceous glands, normalises keratinisation and reduces C. acnes, and it is highly teratogenic so pregnancy must be avoided. Lipids and liver enzymes are monitored, and mucocutaneous dryness is expected.

Option by option

A. It reduces sebaceous gland size and sebum, and is strongly teratogenic (correct)
Correct. Sebum reduction and teratogenicity are key facts.
B. It blocks androgen receptors, and is safe in pregnancy
It is not an anti-androgen.
C. It kills Cutibacterium only, and is safe in pregnancy
It is not safe in pregnancy and acts beyond bacterial killing.
D. It is an antifungal that lowers cholesterol
It is not an antifungal and raises lipids.

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, It reduces sebaceous gland size and sebum, and is strongly teratogenic. Isotretinoin shrinks sebaceous glands, normalises keratinisation and reduces C.

Why is "It blocks androgen receptors, and is safe in pregnancy" not the answer?

It is not an anti-androgen.

Why is "It kills Cutibacterium only, and is safe in pregnancy" not the answer?

It is not safe in pregnancy and acts beyond bacterial killing.

Why is "It is an antifungal that lowers cholesterol" not the answer?

It is not an antifungal and raises lipids.

What concept does this question test?

It tests Acne: isotretinoin in Dermatology. acnes, and it is highly teratogenic so pregnancy must be avoided. Lipids and liver enzymes are monitored, and mucocutaneous dryness is expected.

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 Acne: isotretinoin?

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.