Vitamins and minerals: hypercarotenaemia: practice question

A Biochemistry 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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Biochemistry · Vitamins and minerals: hypercarotenaemia

Sample item

A 2-year-old fed large daily servings of mashed carrot and papaya has yellow-orange palms, soles and nasolabial folds. The sclerae are white and serum bilirubin is normal. What explains the skin colour?

ADietary pigments accumulating in skin lipidsBFailure of haem breakdown to biliverdinCBilirubin bound to cutaneous elastic tissueDRetinol overload within hepatic stellate cells

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

The answer and the reasoning

A. Dietary pigments accumulating in skin lipids

Excess intake of provitamin A pigments stains the stratum corneum and subcutaneous fat, most visibly on palms, soles and nasolabial folds. The sclerae stay white because they take up little of the pigment, which separates it from jaundice. It is harmless and resolves when the intake is reduced.

Option by option

A. Dietary pigments accumulating in skin lipids (correct)
Correct. Carotene-type pigments from the diet deposit in skin lipids and spare the sclerae.
B. Failure of haem breakdown to biliverdin
Impaired haem catabolism would raise bilirubin, which is normal here.
C. Bilirubin bound to cutaneous elastic tissue
Bilirubin staining would colour the sclerae and the serum bilirubin would be raised.
D. Retinol overload within hepatic stellate cells
Retinol excess causes liver and bone toxicity, not a harmless yellow skin colour with white sclerae.

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 Biochemistry question

What is the answer to this Biochemistry question?

The best answer is A, Dietary pigments accumulating in skin lipids. Excess intake of provitamin A pigments stains the stratum corneum and subcutaneous fat, most visibly on palms, soles and nasolabial folds.

Why is "Failure of haem breakdown to biliverdin" not the answer?

Impaired haem catabolism would raise bilirubin, which is normal here.

Why is "Bilirubin bound to cutaneous elastic tissue" not the answer?

Bilirubin staining would colour the sclerae and the serum bilirubin would be raised.

Why is "Retinol overload within hepatic stellate cells" not the answer?

Retinol excess causes liver and bone toxicity, not a harmless yellow skin colour with white sclerae.

What concept does this question test?

It tests Vitamins and minerals: hypercarotenaemia in Biochemistry. The sclerae stay white because they take up little of the pigment, which separates it from jaundice. It is harmless and resolves when the intake is reduced.

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 Vitamins and minerals: hypercarotenaemia?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry 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.