Adrenal insufficiency: Addison's disease and secondary adrenal insufficiency

Question 1

What is Addison’s disease

Answer 1

Addison’s disease = primary adrenal insufficiency. The body doesn’t produce enough aldosterone/cortisol and androgens

Question 2

Describe the epidemiology of Addison’s disease

Answer 2

• Rare: 0.8 per 100,000
• More common in females
• Can be fatal

Question 3

Describe the pathology of Addison’s disease

Answer 3

• The entire adrenal cortex is destroyed, resulting in reduced glucocorticoid (cortisol), mineralocorticoid (aldosterone) and androgen production
• In Addison’s, reduced cortisol levels lead to increased CRH and ACTH production

Question 4

Describe the causes of Addison’s disease

Answer 4

1. ) Addison’s: autoimmune adrenalitis (90% of cases + most common cause in UK)
2. ) Adrenal TB (most common cause worldwide)
3. ) Surgical removal of adrenal glands
4. ) Adrenal haemorrhage/infarction (in meningococcal septicaemia)
5. ) Malignant infiltration (lung/breast/renal cancer)

FOR SECONDARY adrenal insuffiency, causes include:

• steroids
• congenital
• CRH deficiency
• Trauma
• Radiotherapy

Also associated with other autoimmune conditions: autoimmune thyroid disease, ovarian failure, pernicious anaemia, T1DM

Question 5

Describe the signs of Addison’s disease

Answer 5

• Hyperpigmentation of skin
• Low grade fever
• Postural hypertension
• Tachycardia

Question 6

Describe the signs of Addison’s disease

Answer 6

• Hyperpigmentation of skin (caused by stimulation of melanocytes by excess ACTH)
• Postural hypotension
• Hypoglycaemia
• Vitiligo + loss of body hair in females

Question 7

Describe the symptoms of Addison’s disease

Answer 7

• Fatigue
• Nausea and vomiting
• Abdominal pain
• Weight loss
  Depression/tearfulness
• Anorexia
• Impotence
• Amenorrhoea

Question 8

What are the investigations and diagnosis for Addison’s?

Answer 8

1. ) Short ACTH stimulation test:
   - Take baseline cortisol
   - Give ACTH then measure cortisol level: shows failure of exogenous ACTH to increase plasma cortisol
   - In Addison’s - cortisol remains low after giving ACTH
   - remember: wont distinguish primary and secondary
2. ) Plasma ACTH levels
   - High ACTH: with low/normal cortisol will confirm primary
   - Low ACTH: with low cortisol indicates secondary/tertiary

3.) U&E: shows high plasma renin/eosinophilia/raised urea

Others: adrenal antibodies: 21-hydroxylase and Adrenal CXR

Question 9

Describe the management and treatment options

Answer 9

1.) Glucorticoid and mineralocorticoid hormone replacements

Question 10

Describe the management and treatment options

Answer 10

1. ) Glucocorticoid replacement: oral hydrocortisone/prednisolone to replace cortisol
2. ) mineralocorticoid hormone replacement: fludrocortisone to replace aldosterone

Question 11

What is an Addisonian crisis?

Answer 11

• Sudden need for aldosterone and cortisol
• Patient will present with:
• Abdo +back pain
• Muscle cramps
• Confusion
• Hypotension
• Hypoglycaemia
• Hypovolaemic shock
• To treat: use fluids and IV hydrocortisone