Addison's Disease

Question 1

Addison’s Disease

What is it?

Causes

Answer 1

A.k.a Primary Adrenal Insufficiency

Addison’s Disease refers to the specific condition where the adrenal glands have been damaged, resulting in a reduction in the secretion of cortisol and aldosterone

Causes:

• Autoimmune: associated with other AI conditions
• TUBERCULOSIS COMMON
• Metastatic malignancy
• Haemorrhage (Waterhouse-Friedrichson: haemorrhage of adrenal glands)

Question 2

Secondary Adrenal Insufficiency

What is it

Causes

Answer 2

Inadequate ACTH stimulating the adrenal glands resulting in low cortisol

CAUSES

• loss or damage to the pituitary gland: surgery to remove a pituitary tumour or infection
• loss of blood flow or radiotherapy
• Sheehan’s syndrome: massive blood loss during childbirth leads to pituitary gland necrosis.

Question 3

Tertiary Adrenal Insufficiency

What is it

Causes

Answer 3

Tertiary Adrenal Insufficiency is the result of inadequate CRH release by the hypothalamus.

CAUSE:
- long term oral steroids (for more than 3 weeks)

Question 4

Clinical Features

Answer 4

Fatigue
Nausea
Cramps
Abdominal pain
Reduced libido

In primary: hyperpigmentation

Postural Hypotension

Question 5

investigations

Answer 5

U+Es:
- Hyponatraemia (low sodium)

• Hyperkalaemia (high potassium) -> metabolic acidosis (normal anion gap)

? Screening: 9am Cortisol test can give an idea of adrenal insufficiency

A short synacthen test is the test of choice to diagnose adrenal insufficiency

Adrenal autoantibodies are present in 80% of autoimmune adrenal insufficiency: adrenal cortex antibodies and 21-hydroxylase antibodies

CT / MRI adrenals if suspecting an adrenal tumour, haemorrhage or other structural pathology (not recommended by NICE for autoimmune adrenal insufficiency)

MRI pituitary gives further information about pituitary pathology

Question 6

Short Synacthen Test

Answer 6

The test involves giving synacthen, which is synthetic ACTH.

The blood cortisol is measured at baseline, 30 and 60 minutes after administration.

A failure of cortisol to rise (less than double the baseline) indicates primary adrenal insufficiency (Addison’s disease).

Question 7

Management

Answer 7

Hydrocortisone replaces cortisol

Fludrocortisone replaces aldosterone if aldosterone is also insufficient

Patients are given a steroid card and an emergency ID tag to alert emergency services that they are dependent on steroids for life.

Doses should not be missed as they are essential to life.

Doses are doubled during an acute illness until they have recovered to match the normal steroid response to illness.

Question 8

Addisonian Crisis

Management

Answer 8

Parenteral steroids (i.e. IV hydrocortisone 100 - 200mg stat then 100mg every 6 hours)

IV fluid resuscitation

Correct hypoglycaemia

Careful monitoring of electrolytes and fluid balance

Question 9

Addisonian Crisis

Clinical Features

Answer 9

Hypotension

Hypoglycaemia

Abdominal Pain