Addison's disease

Question 1

What is it?

Answer 1

destruction of the entire adrenal cortex -> mineralocorticoid, glucocorticoid and sex deficiency

Question 2

What is the most common cause of primary hypoadrenalism

Answer 2

autoimmune - abs directed against adrenal cortex and/or 21-hydroxylase

Question 3

Explain the hypothalamic pituitary adrenal axis

Answer 3

Hypothalamus releases corticotrophic releasing hormone (CRH)
Anterior pituitary releases adrenocorticotrophic hormone (ACTH)
Adrenals release cortisol which has -ve feedback effect on hypothalamus and ant. pituitary

Question 4

What are the symptoms of primary adrenal insufficiency?

Answer 4

1. Lethargy, depression, low mood
2. Anorexia + WL
3. GI: N+V, diarrhoea, constipation, abdo pain
4. Skin pigmentation - esp. palmar creases, vitiligo
5. Postural hypotension

Question 5

When should you always consider Addisons?

Answer 5

unexplained abdo pain or vomiting

Question 6

What tests would you do?

Answer 6

1. Hyponatraemia + hyperkalaemia
2. Hypoglycaemia (low cortisol)
3. Uraemia
4. Raised Ca2+
5. Eosinophilia (cortisol has anti-inflammatory effects)
6. CXR if TB hx

Question 7

What test is diagnostic for Addisons?

Answer 7

Short ACTH stimulation test:
measure plasma cortisol before and 30 mins after IM TETRACOSACTIDE (SynACTHen - ACTH analogue)
Addisons is excluded if 30min cortisol >550nmol/L

Question 8

What is the treatment if primary adrenal insufficiency ?

Answer 8

Replace steroids 3x daily to mimic circadian rhythm:
- glucocorticoids - oral hydrocortisone/prednisolone
- mineralocorticoids - oral fludrocortisone
Give a steroid drug card and bracelet

Question 9

What should you warn patients against when on treatment?

Answer 9

do not abruptly STOP steroids

Question 10

When should the treatment dose be doubled?

Answer 10

infection/trauma/surgery/nightshift work

Question 11

When should treatment dose be increased?

Answer 11

pregnancy and before strenuous activity/exercise

Question 12

What is secondary adrenal insufficiency?

Answer 12

iatrogenic - long term steroid therapy leading to suppression of the pituitary adrenal axis

Question 13

How does secondary adrenal insufficiency present?

Answer 13

vague sx of feeling unwell
no skin hyper pigmentation as ACTH is reduced
sx becomes apparent once steroids are stopped

Question 14

How would u differentiate between primary and secondary adrenal insufficiency?

Answer 14

Secondary - ACTH levels are low and mineralocorticoid production is intact

Question 15

What is the treatment of secondary adrenal insufficiency?

Answer 15

adrenals recover if log term steroids are slowly weaned off - long + difficult
Oral hydrocortisone

Question 16

What are causes of addisonian crisis?

Answer 16

infection, trauma, surgery, missed meds

cause acute exacerbation of chronic insufficiency

Question 17

How can a pt in addisonian crisis present?

Answer 17

Shock in pt w known Addison’s (tachycardia, postural hypotension, confusion, oliguria etc.)

Question 18

What is the management of an Addisonian crisis?

Answer 18

1. IV HYDROCORTISONE 100mg stat
2. IV fluid bolus
3. Bloods for cortisol + ACTH (rx before results if suspected)
4. K+ can be raised - calcium gluconate
5. Na can be low - rehydrate + steroids
6. Monitor glucose
7. Rx for poss infection i.e. cultures, abx

Question 19

What is the continuing treatment for Addisonian crisis?

Answer 19

Glucose IV if hypoglycaemic
IV fluids to correct U&E imbalances 
Continue hydrocortisone IV or IM
Change to oral steroids after 72hrs if pt gd. 
Consider fludrocortisone