Disorders of the human adrenal gland

Question 1

What are the causes of primary adrenal insufficiency?

Answer 1

Addison’s
Congenital adrenal hyperplasia
Adrenal TB/malignancy

Question 2

What are the causes of secondary adrenal insufficiency?

Answer 2

Lack of ATCH stimulation
Iatrogenic (excess exogenous steroid)
Pituitary/hypothalamic disorders

Question 3

What is the most common cause of primary and secondary adrenal insufficiency?

Answer 3

Primary - Addison’s

Secondary - exogenous steroid use

Question 4

What is Addison’s disease and at what stage in the pathogenesis does it become symptomatic?

Answer 4

Autoimmune destruction of the adrenal cortex.

Symptomatic after >90% of the adrenal cortex has been destroyed.

Question 5

What are the key clinical features of Addison’s?

Answer 5

Anorexia, weight loss
Fatigue/lethargy
Dizziness/hypotension 
Abdo pain, vomiting, diarrhoea
Skin pigmentation (due to MSH )

Question 6

How can adrenal irusuffiency be diagnosed?

Answer 6

Biochemistry
- low sodium, high potassium and hypoglycaemia

Short SYNACTHEN test
- plasma cortisol mesures before and 30 mins after IV ACTH measurement

ACTH levels
- should be high

Renin/aldosterone levels
- renin should be high and aldosterone low

Adrenal autoantibodies

Question 7

How can adrenal insufficiency be managed?

Answer 7

Hydrocortisone to replace cortisol

Fludrocortisone to replace aldosterone

Question 8

What are sick day rules?

Answer 8

If a person is unwell or on maintenance steroids, cortisol dose should be doubled for 3 days.

Question 9

How do exogenous steroids affect cortisol production?

Answer 9

High exogenous steroids switches off the hypothalamus and ant pituitary. Chronic suppression can cause adrenal atrophy.

Question 10

What clinical features differentiates primary and secondary adrenal insufficiency?

Answer 10

Secondary - will be pale skin (no ATCH) and normotensive (aldosterone still intact).

Question 11

How is secondary adrenal insufficiency treated?

Answer 11

With hydrocortisone only - aldosterone levels are normal.

Question 12

What are key clinical features of cortisol excess?

Answer 12

Easy bruising
Facial plethora
Striae 
Proximal myopathy
Osteoporosis
Tendency to hyperglycaemia 
Central fat deposition
Buffalo hump
Pour wound healing

Question 13

What are the causes of Cushing’s Syndrome?

Answer 13

ACTH dependent

• pituitary adenoma (Cushing’s disease)
• ectopic ATCH
• ectopic CRH

ATCH independent

• adrenal adenoma
• adrenal carcinoma
• nodular hyperplasia

Iatrogenic long-term exogenous steroid use.

Question 14

How can Cushing’s Syndrome be diagnosed?

Answer 14

Firstly, establish cortisol excess.

• dexamethasone suppression test
• 24 hour urinary free cortisol
• late night salivary cortisol

Secondly, establish source of cortisol excess.
- Measure ACTH

Question 15

When measuring ACTH to determine the cause of Cushing’s, discuss action taken if ACTH levels are normal/high or undetectable.

Answer 15

Normal/high - CRH stimulation test.

• if no change in levels then carry out CT of chest/abdo/pelvis - ECTOPIC ACTH source.
• if exaggerated rise in ACTH then pituitary MRI - PITUITARY ACTH source.

Undetectable - adrenal CT scan.
- likely PRIMARY ADRENAL PROBLEM.

Question 16

What 2 disorders of the adrenal gland often result in hypertension?

Answer 16

Primary aldosteronism

Phaeochromocytoma

Question 17

What areas of the body can the effects of MSH in primary adrenal insufficiency be seen?

Answer 17

Skin pigmentation in buchal mucosa and palmar creases.