Addison's disease

Question 1

What is addison’s disease?

Answer 1

Primary adrenal insufficiency → decreased production of adrenocortical hormones (reduced cortisol and aldosterone)

Question 2

Describe the epidemiology of addison’s disease

Answer 2

F>M
● 80% in UK due to autoimmune

Question 3

What can cause addison’s disease?

Answer 3

• Causes → Autoimmune (more developed countries) & Tuberculosis (more common worldwide)
• May also be caused by metastases (eg. bronchial carcinoma)

Question 4

What are the risk factors for addison’s disease?

Answer 4

• female
• presence of adrenocortical autoantibodies
• adrenal haemorrhage
• anticoagulant use

Question 5

What is meant by “addisonian crisis”?

Answer 5

May be precipitated by sudden withdrawal of steroids if patient on long-term steroid medication, sepsis or surgery.

Question 6

What are the presenting symptoms of addison’s disease?

Answer 6

1. Chronic Presentation - the symptoms tend to be VAGUE and NON-SPECIFIC
   o Dizziness
   o Anorexia
   o Weight loss
   o Diarrhoea and Vomiting
   o Abdominal pain
   o Lethargy
   o Weakness
   o Depression
   o Darkened skin -ve feedback causes increased ACTH leading to increased POMC, leading to increased α-MSH
   ● Acute Presentation (Addisonian Crisis)
   o Acute adrenal insufficiency
   o Major haemodynamic collapse
   o Precipitated by stress (e.g. infection, surgery)

Question 7

What investigations are used to diagnose/ monitor addison’s disease?

Answer 7

1. ACTH Stimulation Test → short Synacthen test
   - Synacthen should stimulate cortisol secretion from adrenal glands. Will not occur in addison’s.
2. Morning Serum Cortisol → If short synacthen test unavailable (ie. in primary care). Take blood between 8-9am, when cortisol levels peak. If low then suspect Addison’s.
3. Serum Electrolytes (Due to Aldosterone Deficiency) → hyponatraemia + hyperkalaemia
4. Hypoglycaemia
5. Metabolic Acidosis with normal anion gap
6. FBC → anaemia

Question 8

How is addison’s disease managed?

Answer 8

1. Stable (Glucocorticoid + Mineralocorticoid) → Hydrocortisone (given in 2 or 3 divided doses) + Fludrocortisone
   - Intercurrent Illnesses ⇒ hydrocortisone (glucocorticoid) dose should be doubled and fludrocortisone dose should stay the same.
2. Addisonian Crisis → IV hydrocortisone, Fluid Resuscitation, Glucose (if hypoglycaemia)
   - Precipitated by sudden withdrawal of steroids, illness or surgery

Question 9

What signs of addison’s disease can be found on physical examination?

Answer 9

1. Postural hypotension
2. Increased pigmentation
   o More noticeable on buccal mucosa, scars, skin creases (palmar creases), nails and pressure points
3. Loss of body hair in women (due to androgen deficiency)
4. Associated autoimmune condition - vitiligo
5. Addisonian Crisis Signs
   o Hypotensive shock
   o Tachycardia
   o Pale
   o Cold
   o Clammy
   o Oliguria

Question 10

What complications may arise from addison’s disease?

Answer 10

● HYPERKALAEMIA
● Death during Addisonian crisis

Question 11

Summarise the prognosis of addison’s disease

Answer 11

1. Adrenal function rarely recovers
2. Normal life expectancy if treated
3. Autoimmune Polyendocrine Syndrome
   o Type 1 - autosomal recessive disorder caused by mutations in the AIRE gene. Consists of the following diseases:
4. Addison’s disease
5. Chronic mucocutaneous candidiasis
6. Hypoparathyroidism
   o Type 2 - also known as Schmidt’s Syndrome
7. Addison’s disease
8. Type 1 Diabetes
9. Hypothyroidism
10. Hypogonadism