History/Exam: Addison's Disease

Question 1

What is Addison’s disease?

Answer 1

A rare autoimmune endocrine disorder causing primary adrenal insufficiency. Autoantibodies are directed against the adrenal glands resulting in destruction of the adrenal cortex and decreased cortisol release.

Question 2

Adrenal insufficiency can be divided into primary and secondary.

What are some causes of 1ary adrenal insufficiency?

Answer 2

• Addison’s disease (80%)
• Adrenal adenomas
• HIV
• TB
• Congenital adrenal hyperplasia

Question 3

What is 2ary adrenal insufficiency?

Answer 3

Due to the impairment of the pituitary gland to produce ACTH.

Question 4

What is 1ary adrenal insufficiency?

Answer 4

Due to a problem within the adrenal glands causing impairment of cortisol production.

Question 5

What are the 3 causes of 2ary adrenal insufficiency?

Answer 5

1) Exogenous steroid use (most common)

2) Pituitary adenoma

3) Hypothalamic tumour.

Question 6

What is the most common cause of 2ary adrenal insufficiency?

Answer 6

Exogenous steroid use

Question 7

What symptoms should you ask about for Addison’s disease?

Answer 7

Note - these are vague and are due to low circulating levels of cortisol.

• Tiredness
• Weight loss
• N&V
• Abdo pain & diarrhoea
• Weakness
• Confusion
• Syncope, dizziness on standing
• Joint pains
• Myalgia
• Fever
• Menstrual disturbance
• Obvious skin changes (hyperpigmentation)

Question 8

What conditions should you specifically ask about in PMH and FH for Addison’s?

Answer 8

Associated autoimmune conditions:
- vitiligo
- thyroid disease
- T1D

Question 9

What should you include in SH iin Addison’s?

Answer 9

• Travel
• TB risk assessment
• HIV risk assessment

Question 10

Possible examination findings in 1ary adrenal insufficiency?

Answer 10

1) Widespread hyperpigmentation

2) Women may have a loss of axillary or pubic hair

3) BP may be low (note - if BP is raised this would almost exclude a diagnosis of Addison’s disease)

4) Look for evidence of other associated autoimmune conditions e.g. vitiligo

5) Look for medicAlert bracelet or necklace

Question 11

What causes hyperpigmentation in 1ary adrenal insufficiency?

Answer 11

It is caused by the stimulant effect of excess adrenocorticotrophic hormone (ACTH) on the melanocytes to produce melanin

Question 12

Hyperpigmentation in 1ary vs 2ary adrenal insufficiency

Answer 12

1ary –> hyperpigmentation present (due to increased ACTH in response to low cortisol)

2ary –> no hyperpigmentation (due to low ACTH due to pituitary problem)

Question 13

Where is hyperpigmentation particularly evident in Addison’s?

Answer 13

• palmar creases
• pressure areas (e.g. elbows)
• buccal mucosa
• skin creases
• previous surgical scars
• light-exposed areas

Question 14

How is BP affected in Addison’s?

Answer 14

Hypotension

Question 15

What are the 3 autoimmune conditions assoicated with Addison’s?

Answer 15

1) Vitiligo (look for depigmented skin)

2) Autoimmune thyroid disease

3) Type 1 diabetes

Question 16

What are the 7 investigations would you do for suspected adrenal insufficiency?

Answer 16

1) BP

2) Blood glucose

3) FBC

4) U&Es

5) 9am cortisol

6) Short synacthen test

7) Serum ACTH

Question 17

What blood tests can be done in Addison’s?

Answer 17

1) FBC

2) U&Es

3) LFTs

4) Plasma renin and aldosterone

5) Adrenal autoantibodies

6) TFTs

7) Serum ACTH

Question 18

What may FBC show in Addison’s?

Answer 18

Normocytic anaemia, lymphocytosis or associated eosinophilia

Question 19

What may U&Es show in Addison’s?

Answer 19

• hyponatraemia
• hyperkalaemia
• occasionally hypercalcaemia

Question 20

What 9am cortisol level is indicative of adrenal insufficiency?

Answer 20

<100

Question 21

What 9am cortisol level is a grey area and would need a short synacthen test to further investigate?

Answer 21

100-400

Question 22

What 9am cortisol level is indicative of adrenal sufficiency?

Answer 22

> 400

Question 23

What is the short synacthen test?

Answer 23

The test of choice for diagnosing adrenal insufficiency.

1) Guve dose of synacthen (synthetic ACTH)

2) Blood cortisol is checked before, 30 and 60 minutes after dose

3) A failure of cortisol to double indicates 1ary adrenal insufficiency

Question 24

What 2 conditions does a failure of cortisol to double in a short synacthen test indicate?

Answer 24

1) Primary adrenal insufficiency (Addison’s disease)

2) Very significant adrenal atrophy after a prolonged absence of ACTH in secondary adrenal insufficiency

Question 25

Adrenal autoantibodies should be measured as these are positive in around 70% of cases of Addison’s disease.

What 2 autoantibodies may be present in autoimmune adrenal insufficiency?

Answer 25

1) Adrenal cortex antibodies

2) 21-hydroxylase antibodies

Question 26

ACTH can be measured directly.

Describe ACTH level in 1ary vs 2ary adrenal insufficiency

Answer 26

1ary - high

2ary - low

Question 27

Why should you check TFTs in suspected Addison’s?

Answer 27

As there is a high incidence of associated autoimmune thyroid disorders

Question 28

What is treatment for Addisonian crisis?

Answer 28

1) Admission

2) Hydrocortisone 100mg (IM or IV)

3) 1 litre 0.9% saline infused over 30-60 mins or with dextrose if hypoglycaemic

4) Continue hydrocortisone 6 hourly until the patient is stable

5) Oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days

Question 29

Why is hydrocortisone given in adrenal crisis?

Answer 29

As has both mineralocorticoid and glucocorticoid actions