Paeds endocrine

Question 1

Congenital adrenal hyperplasia:
1. What is it a congenital deficiency of?
2. What does it lead to underproduction of?
3. What does it lead to overproduction of?
4. What is the inheritance pattern?

Answer 1

1. 21-hydroxylase enzyme
2. Cortisol and aldosterone
3. Androgens (testosterone)
4. Autosomal recessive

Question 2

What is 21-hydroxylase enzyme responsible for?

Answer 2

Converting progesterone into aldosterone and cortisol

Question 3

Why do you get increased testosterone in CAH?

Answer 3

Extra progesterone that cannot be converted in aldosterone and cortisol, gets converted into testosterone

Question 4

How do patients with mild congenital adrenal hyperplasia present?

Answer 4

• Tall for age
• Skin hyperpigmentation
• Facial hair
• Early puberty
• Absent periods
• Large penis, small testicles

Question 5

How do patients with severe CAH present? What is a key feature in female patients?

Answer 5

• At birth with hyponatraemia, hyperkalemia and hypoglycaemia
• Female patients can present with virtualised genitalia known as ‘ambiguous genitalia’ and an enlarged clitoris

Question 6

What is the management of CAH?

Answer 6

• Cortisol replacement - hydrocortisone
• Aldosterone replacement - fludrocortisone

Question 7

What are the two types of adrenal insufficiency?

Answer 7

• Primary adrenal insufficiency (addisions)
• Secondary adrenal insufficiency

Question 8

What are the ACTH, cortisol, aldosterone and renin levels in primary adrenal insufficiency?

Answer 8

• ACTH - high
• Cortisol - low
• Aldosterone - low
• Renin - high

Question 9

What are the ACTH, cortisol, aldosterone and renin levels in secondary adrenal insufficiency?

Answer 9

• ACTH - low
• Cortisol - low
• Aldosterone - normal
• Renin - normal

Question 10

What causes secondary adrenal insufficiency?

Answer 10

Inadequate ACTH resulting in low cortisol

Question 11

What happens in Addisons disease? What is the most common cause?

Answer 11

• Damage to the adrenal glands resulting in reduced secretion of cortisol and aldosterone
• Autoimmune

Question 12

What test can be used to confirm adrenal insufficiency?

Answer 12

Short Synacthen Test (ACTH stimulation test)

Question 13

How would the short synachthen test indicate primary adrenal insufficiency?

Answer 13

The cortisol levels would not rise as the problem is independent of ACTH

Question 14

What is synacthen?

Answer 14

Synthetic ACTH

Question 15

What is the management of adrenal insufficiency?

Answer 15

Replace cortisol (hydrocortisone) and aldosterone (fludrocortisone) as required

Question 16

What are the two causes of congenital hypothyroidism?

Answer 16

• Dysgenesis - underdeveloped thyroid gland
• Dyshormonogenesis - fully developed thyroid that does not produce enough hormone

Question 17

When is congenital hypothyroidism screened for?

Answer 17

On the newborn blood spot test

Question 18

Acquired hypothyroidism:
1. What is the most common cause?
2. What is another name for this?
3. What 2 antibodies is this associated with?

Answer 18

1. Autoimmune thyroiditis
2. Hashimoto’s thyroiditis
3. Antithyroglobulin antibodies, anti-TPO antibodies

Question 19

What is the management of congenital/acquired thyroiditis?

Answer 19

Levothyroxine