Papulosquamous disorders: adverse effect of coal tar: 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 · Papulosquamous disorders: adverse effect of coal tar

Sample item

A patient with chronic plaque psoriasis applies crude coal tar to the plaques on the legs daily. After a few weeks, follicular papulopustules appear in the treated areas. What is the likely explanation?

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

The answer and the reasoning

B. Tar folliculitis

Coal tar can occlude and irritate hair follicles, causing tar folliculitis, and it also stains clothing, smells and causes photosensitivity. Folliculitis is managed by stopping tar or reducing the frequency of application.

Option by option

  • A. Pustular psoriasis flare

    A pustular psoriasis flare would be diffuse with fever and not confined to follicles in treated areas.

  • B. Tar folliculitis (correct)

    Correct. Follicular pustules confined to tar-treated skin indicate tar folliculitis.

  • C. Contact urticaria

    Contact urticaria produces transient wheals within minutes, not follicular pustules.

  • D. Tinea corporis

    Tinea corporis causes annular scaly plaques with a raised edge.

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.

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Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is B, Tar folliculitis. Coal tar can occlude and irritate hair follicles, causing tar folliculitis, and it also stains clothing, smells and causes photosensitivity.

Why is "Pustular psoriasis flare" not the answer?

A pustular psoriasis flare would be diffuse with fever and not confined to follicles in treated areas.

Why is "Contact urticaria" not the answer?

Contact urticaria produces transient wheals within minutes, not follicular pustules.

Why is "Tinea corporis" not the answer?

Tinea corporis causes annular scaly plaques with a raised edge.

What concept does this question test?

It tests Papulosquamous disorders: adverse effect of coal tar in Dermatology. Folliculitis is managed by stopping tar or reducing the frequency of application.

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 Papulosquamous disorders: adverse effect of coal tar?

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.