Vitamins and minerals: Bitot spots in vitamin A deficiency: 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.

Try it

Biochemistry · Vitamins and minerals: Bitot spots in vitamin A deficiency

Sample item

A malnourished 4-year-old has poor vision in dim light and foamy, triangular, greyish patches on the bulbar conjunctiva that do not wet with tears. Which histological change underlies these patches?

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

The answer and the reasoning

D. Keratinising squamous metaplasia with loss of goblet cells

Retinoic acid maintains differentiation of mucus-secreting epithelium. In vitamin A deficiency, conjunctival epithelium undergoes keratinising squamous metaplasia with loss of goblet cells, producing dry, foamy Bitot spots. Night blindness is the earliest symptom and keratomalacia the most severe.

Option by option

  • A. Subconjunctival haemorrhage from fragile perifollicular capillaries

    Capillary fragility and haemorrhage describe scurvy, not these dry plaques.

  • B. Lipid deposition within the superficial layers of the corneal stroma

    Lipid deposition describes arcus or corneal dystrophies and has no link to night blindness.

  • C. Goblet cell hyperplasia with excess mucus secretion by the epithelium

    Goblet cells are lost, not increased, in this deficiency.

  • D. Keratinising squamous metaplasia with loss of goblet cells (correct)

    Correct. Keratinising metaplasia with goblet cell loss produces the dry foamy plaques.

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 Biochemistry questions

Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is D, Keratinising squamous metaplasia with loss of goblet cells. Retinoic acid maintains differentiation of mucus-secreting epithelium.

Why is "Subconjunctival haemorrhage from fragile perifollicular capillaries" not the answer?

Capillary fragility and haemorrhage describe scurvy, not these dry plaques.

Why is "Lipid deposition within the superficial layers of the corneal stroma" not the answer?

Lipid deposition describes arcus or corneal dystrophies and has no link to night blindness.

Why is "Goblet cell hyperplasia with excess mucus secretion by the epithelium" not the answer?

Goblet cells are lost, not increased, in this deficiency.

What concept does this question test?

It tests Vitamins and minerals: Bitot spots in vitamin A deficiency in Biochemistry. In vitamin A deficiency, conjunctival epithelium undergoes keratinising squamous metaplasia with loss of goblet cells, producing dry, foamy Bitot spots. Night blindness is the earliest symptom and keratomalacia the most severe.

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 Vitamins and minerals: Bitot spots in vitamin A deficiency?

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.