Addison's disease

Question 1

What is addison’s disease?

Answer 1

Addison’s disease is the most common form of adrenal insufficiency.

Adrenal insufficiency occurs where there is destruction of the adrenal cortex and reduced output of adrenal hormones

Question 2

What are the two types of adrenal insufficiency?

Answer 2

1. Primary hypoadrenalism
2. Secondary hypoadrenalism

Question 3

What is primary hypoadrenalism?

Answer 3

In primary hypoaldosteronism conditions, there is the destruction of the adrenal cortex. The presentation is notoriously varied and vague. It is potentially fatal if untreated. There will be a lack of secretion of cortisol, aldosterone and sex hormone.

Usually due to autoimmune disease

Question 4

What is secondary hypoadrenalism?

Answer 4

Due to inadequate secretion of pituitary hormones and thus reduced stimulation of the adrenal glands
aldosterone secretion may remain at normal levels due to stimulation from pituitary independent mechanisms – namely via angiotensin II.
inadequate ACTH from the pituitary gland, leading to a lack of stimulation of the adrenal glands

Question 5

What is tertiary Addison’s disease?

Answer 5

inadequate corticotropin releasing hormone (CRH) from the hypothalamus, resulting in reduced cortisol and aldosterone secretion

Question 6

What hormone stimulates the pituitary to release ACTH?

Answer 6

CRH (corticotrophin releasing hormone)

Question 7

What is the epidemiology of Addison’s disease?

Answer 7

Addison’s disease is rare – it has an incidence of 3-4 per 1,000,000 per year, and a prevalence of 40-60 per 1,000,000.
It is more common in women
Typical age of onset 30 to 50
>90% of cases are a result of autoimmune disease
The remainder are mostly a result of TB.

Question 8

What is the most common cause of Addison’s disease?

Answer 8

autoimmune attack of the adrenal glands

Question 9

Give 5 causes of secondary adrenal insufficiency:

Answer 9

1) tumours e.g. pituitary adenomas
2) surgery to the pituitary
3) radiotherapy
4) Sheehan’s syndrome
5) trauma

Question 10

What is Sheehan’s syndrome?

Answer 10

major post-partum haemorrhage causing avascular necrosis of the pituitary gland

Question 11

What is the main cause of tertiary adrenal insufficiency?

Answer 11

long term exogenous steroid use

Question 12

Describe how long term exogenous steroid use can cause tertiary adrenal insufficiency:

Answer 12

exogenous steroid use causes suppression to the hypothalamus via negative feedback

Question 13

Explain why it is important to slowly withdraw steroid medications:

Answer 13

sudden withdrawal may mean the hypothalamus does not respond fast enough to the sudden lack of negative feedback, meaning the axis does not start up quick enough leading to insufficiency

Question 14

Give 11 presentations associated with adrenal insufficiency:

Answer 14

1) fatigue
2) muscle weakness
3) muscle cramps
4) dizziness and fainting
5) thirst and craving salt
6) weight loss
7) abdominal pain
8) depression
9) reduced libido
10) bronze hyperpigmentation
11) hypotension and postural hypotension

Question 15

When would bronze hyperpigmentation be seen in adrenal insufficiency?

Answer 15

where there are high levels of ACTH which stimulates melanocytes to produce melanin

Question 16

Where is bronze hyperpigmentation usually seen in Addison’s disease?

Answer 16

1) skin creases (palms of hands especially)
2) lips
3) oral mucosa

Question 17

What is the key U+E finding associated with adrenal insufficiency?

Answer 17

hyponatraemia
(Low blood sodium level)

Question 18

Other than hyponatraemia, give 4 other U+E findings that are associated with adrenal insufficiency:

Answer 18

1) hyperkalaemia
2) hypoglycaemia
3) raised urea and creatinine due to dehydration
4) hypercalcaemia

Question 19

Will ACTH be high or low in Addison’s disease?

Answer 19

high

Question 20

Will ACTH be high or low in secondary/tertiary adrenal insufficiency?

Answer 20

Low

Question 21

Give 2 antibodies that are associated with Addison’s disease with autoimmune causes:

Answer 21

1) adrenal cortex antibodies
2) 21-hydroxylase antibodies

Question 22

What is the gold standard investigation for diagnosing Addison’s disease?

Answer 22

short synacthen test

Question 23

Describe the process of the short synacthen test: (2)

Answer 23

1) give a dose of synacthen (synthetic ACTH)
2) check blood cortisol before and 30 and 60 mins after the dose

Question 24

What result would be expected from the short synacthen test in healthy individuals?

Answer 24

cortisol should at least double

Question 25

Failure for cortisol to double in the short synacthen test indicates what two possibilities:

Answer 25

1) Addison’s disease (primary adrenal insufficiency)
2) very significant adrenal atrophy after prolonged absence of ACTH in secondary adrenal insufficiency

Question 26

What management is used for adrenal insufficiency?

Answer 26

Steroid replacement

Question 27

What medication is used for cortisol replacement in adrenal insufficiency?

Answer 27

hydrocortisone

Question 28

What medication is used for aldosterone replacement in adrenal insufficiency?

Answer 28

fludrocortisone

Question 29

Give 3 ways in which patients with adrenal insufficiency can be identified to emergency services that they are dependent on steroids:

Answer 29

1) steroid card
2) ID tag
3) emergency letter

Question 30

What change should be made to steroid replacement in adrenal insufficiency in the event of acute illness?

Answer 30

steroid replacement dosages should be doubled to match the normal steroid response to illness

Question 31

What is Addison’s crisis?

Answer 31

a life-threatening severe adrenal insufficiency

Question 32

Give 4 presentations associated with Addison’s crisis:

Answer 32

1) reduced consciousness
2) hypotension
3) hypoglycaemia
4) hyponatraemia and hyperkalaemia

Question 33

Give 3 potential triggers of Addison’s crisis:

Answer 33

1) infection
2) trauma
3) acute illness

Question 34

Summarise the management strategy for Addison’s crisis:

Answer 34

1) ABCDE and admit to hospital
2) IM or IV hydrocortisone (initial 100mg followed by infusion)
3) IV fluids
4) correct hypoglycaemia with IV dextrose
5) careful monitoring with electrolytes and fluid balance

Question 35

what are the causes of primary hypoaldosteronism?

Answer 35

Addison’s disease

• TB
• metastasis
• Waterhouse-Friderichsen syndrome (meningococcal septicaemia)
• surgical removal of adrenal glands

Question 36

what are causes of secondary hypoaldosteronism?

Answer 36

• pituitary disorders
• congenital disorders
• fracture of the base of the skull
• long term use of exogenous corticosteroids

Question 37

what are the clinical features of hypoaldosteronism?

Answer 37

• hypotension
• skin hyperpigmentation
• hyponatraemia
• fatigue and weakness
• GI symptoms (anorexia, nausea and vomiting, weight loss and salt craving)
• syncope
• hypoglycaemia

Question 38

are both primary Addison’s disease and secondary adrenal insufficiency associated with skin hyperpigmentation?

why?

Answer 38

NO - ONLY ADDISON’S!!!

• POMP is the precursor for ACTH > POMP stimulation > production of melanocyte-stimulating hormones > more melanin in the skin > changes in skin colour

Question 39

is glucose high or low in Addison’s disease?

Answer 39

Low

Question 40

is renin high or low in Addison’s disease?

Answer 40

High

Question 41

is aldosterone high or low in Addison’s disease?

Answer 41

Low

Question 42

how do ACTH levels differ in Addison’s disease and secondary adrenal insufficiency?

Answer 42

• Addison’s = ACTH is high
• secondary adrenal insufficiency = ACTH is low

Question 43

what is found on blood gas for Addison’s disease?

Answer 43

a hyperkalaemic, hyponatraemic and hypoglycaemic metabolic acidosis

Question 44

what serum cortisol level means a ACTH stimulation test should be performed?

Answer 44

100-500 nmol/l

LOW