Endo - Addison's

Question 1

What is the Differential diagnosis for primary adrenal insufficiency?

Answer 1

1. Autoimmune adrenocortical insufficiency (Addison’s disease)
2. TB Adrenals
3. Adrenal metastasis (lung, breast, renal)
4. Lymphoma
5. HIV infections: CMV, NTM
6. Adrenal haemorrhage: SLE, aPLS
7. Amyloidosis

Question 2

What conditions are associated with Addison’s disease?

Answer 2

in 80% of Addison’s disease (+) 21-hydroxylase adrenal antibody.

1. Other autoimmune: vitiligo, T1DM, hypothyroidism

Question 3

What is the cause of secondary adrenal insufficiency?

Answer 3

1. Prolonged iatrogenic steroid use that suppresses the pituitary-adrenal axis with sudden steroid withdrawal
2. Pituitary adenoma (insufficient ACTH)

Question 4

What are the symptoms of adrenal insufficiency?

Answer 4

Tired, tanned, thin, tearful, thirsty,
+/- weakness, anorexia, dizzy, syncopal with postural hypotension, abdominal pain, diarrhoea/constipation, vitiligo, hypoglycaemic

Adrenal crisis: Shock (low BP, tacky, febrile…coma)

Question 5

What blood tests would you start with to investigate AD?

Answer 5

1. FBC (eosinophilia)
2. Urea (rise in dehydration)
3. electrolytes (low Na, high K)
4. glucose (low)
5. TFT (?hypothyroid association)
6. Adrenal autoantibody: 21-hydroxylase

Question 6

How would you investigate adrenal insufficiency?

Answer 6

1. Short synacthen test: cortisol level should rise (without cortisol rise suggests Adrenal insufficiency or AD)
2. 9am ACTH : raised In Addisons disease - pituitary ACTH production ++ without (-) feedback from adrenal cortisol. If low, suggests pituitary adenoma.
3. 21-hydroxylase adrenal Ab: >80% positive in Addison’s disease
4. Plasma renin & aldosterone to check MC
5. CT/ MRI adrenals +/- Ct.MIR pituitary
6. CXR: Malignancy (ACTH-secreting lung Ca/TB

Question 7

What is the characteristic electrolyte disturbance in AD ?

Answer 7

low sodium , high potassium (lack of MC), low glucose (no GC).

Question 8

What is the treatment for an addisonian crisis?

Answer 8

Patient is in hypovoalemic shock with low glucose, low sodium and high potassium:

Give IV HC and fludrocortisone PO

Question 9

What important patient education is needed for anyone taking a steroid?

Answer 9

1. sick day rules: increase dose of steroid
2. Steroid card + medic alert bracelet
3. if unable to tolerate PO needs to seek medical help