Endocrinology: congenital adrenal hyperplasia: practice question

A Pediatrics 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

Pediatrics · Endocrinology: congenital adrenal hyperplasia

Sample item

A 10-day-old boy has vomiting, dehydration, hyponatraemia and hyperkalaemia. 17-hydroxyprogesterone is markedly elevated. What is the diagnosis?

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

The answer and the reasoning

A. 21-hydroxylase deficiency, salt-wasting type

21-hydroxylase deficiency is the commonest form of CAH, and the salt-wasting variety presents in the second week with adrenal crisis. Treatment is hydrocortisone, fludrocortisone and saline. Pyloric stenosis causes hypochloraemic alkalosis with hypokalaemia.

Option by option

  • A. 21-hydroxylase deficiency, salt-wasting type (correct)

    Correct. High 17-OHP with salt wasting confirms 21-hydroxylase deficiency.

  • B. 11-beta-hydroxylase deficiency

    11-beta-hydroxylase deficiency causes hypertension.

  • C. Congenital pyloric stenosis

    Pyloric stenosis causes hypokalaemic alkalosis.

  • D. Primary adrenal haemorrhage

    Adrenal haemorrhage does not raise 17-OHP.

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 Pediatrics questions

Questions about this Pediatrics question

What is the answer to this Pediatrics question?

The best answer is A, 21-hydroxylase deficiency, salt-wasting type. 21-hydroxylase deficiency is the commonest form of CAH, and the salt-wasting variety presents in the second week with adrenal crisis.

Why is "11-beta-hydroxylase deficiency" not the answer?

11-beta-hydroxylase deficiency causes hypertension.

Why is "Congenital pyloric stenosis" not the answer?

Pyloric stenosis causes hypokalaemic alkalosis.

Why is "Primary adrenal haemorrhage" not the answer?

Adrenal haemorrhage does not raise 17-OHP.

What concept does this question test?

It tests Endocrinology: congenital adrenal hyperplasia in Pediatrics. Treatment is hydrocortisone, fludrocortisone and saline. Pyloric stenosis causes hypochloraemic alkalosis with hypokalaemia.

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 Endocrinology: congenital adrenal hyperplasia?

Memorise milestones and the vaccine schedule as tables and revise them often. Then use the flashcards and the other Pediatrics 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.