Drug reactions: propylene glycol in topical minoxidil: 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 · Drug reactions: propylene glycol in topical minoxidil

Sample item

A man on 5 percent topical minoxidil develops an itchy, red, scaly scalp. Patch testing shows allergy to the vehicle and not to minoxidil itself. Which component is the likely allergen?

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

The answer and the reasoning

A. Propylene glycol

Minoxidil solutions contain propylene glycol, which is the usual cause of allergic or irritant contact dermatitis. A propylene glycol-free foam can be used instead.

Option by option

  • A. Propylene glycol (correct)

    Correct. Propylene glycol in the solution is the usual contact allergen.

  • B. Water

    Water is not an allergen.

  • C. Ethanol

    Ethanol is an irritant and drying agent but not a typical allergen.

  • D. Minoxidil sulphate

    Minoxidil sulphate is an active metabolite and not the vehicle component.

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.

More Dermatology questions

Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is A, Propylene glycol. Minoxidil solutions contain propylene glycol, which is the usual cause of allergic or irritant contact dermatitis.

Why is "Water" not the answer?

Water is not an allergen.

Why is "Ethanol" not the answer?

Ethanol is an irritant and drying agent but not a typical allergen.

Why is "Minoxidil sulphate" not the answer?

Minoxidil sulphate is an active metabolite and not the vehicle component.

What concept does this question test?

It tests Drug reactions: propylene glycol in topical minoxidil in Dermatology. A propylene glycol-free foam can be used instead.

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 Drug reactions: propylene glycol in topical minoxidil?

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.