Addison's Disease Flashcards
What is Addison’s disease?
Addison’s disease, also known as primary adrenal insufficiency, is a rare condition where the adrenal glands do not produce enough cortisol and aldosterone.
What are the main symptoms of Addison’s disease?
Fatigue, weight loss, muscle weakness, hypotension, hyperpigmentation, nausea, vomiting, and abdominal pain.
What causes Addison’s disease?
It is most commonly caused by autoimmune destruction of the adrenal cortex. Other causes include infections (e.g., tuberculosis), metastatic cancer, and adrenal haemorrhage.
What is the pathophysiology of Addison’s disease?
The destruction of the adrenal cortex leads to insufficient production of glucocorticoids (cortisol) and mineralocorticoids (aldosterone), disrupting metabolic and electrolyte balance.
How prevalent is Addison’s disease?
It is a rare condition, with an estimated prevalence of 100-140 cases per million people in the UK.
What are the main risk factors for Addison’s disease?
Autoimmune conditions, family history of adrenal insufficiency, and certain infections like tuberculosis.
What clinical examination findings might indicate Addison’s disease?
Hyperpigmentation of the skin and mucous membranes, postural hypotension, dehydration, and generalised weakness.
What investigations are used to diagnose Addison’s disease?
Initial investigations include serum cortisol, ACTH stimulation test, electrolytes, and glucose levels. Imaging (e.g., CT/MRI) may be used to assess adrenal gland morphology.
What electrolyte abnormalities are seen in Addison’s disease?
Hyponatraemia, hyperkalaemia, and sometimes hypoglycaemia.
What is the ACTH stimulation test and its role in diagnosing Addison’s disease?
It involves measuring cortisol levels before and after administering synthetic ACTH. A failure of cortisol levels to rise confirms adrenal insufficiency.
What are the main differential diagnoses for Addison’s disease?
Secondary adrenal insufficiency, hypothyroidism, chronic fatigue syndrome, depression, and gastrointestinal disorders causing weight loss.
How does Addison’s disease affect sodium and potassium levels?
Aldosterone deficiency leads to sodium loss (hyponatraemia) and potassium retention (hyperkalaemia).
What are the signs of an Addisonian crisis?
Severe hypotension, hypovolaemic shock, abdominal pain, vomiting, and confusion.
What are the types of management for Addison’s disease?
Management includes lifelong hormone replacement therapy with hydrocortisone (for cortisol) and fludrocortisone (for aldosterone).
What is the conservative management for Addison’s disease?
Patient education on recognising symptoms of adrenal crisis and how to adjust steroid doses during illness or stress.
What is the medical management for Addison’s disease?
Hormone replacement therapy with hydrocortisone and fludrocortisone. Additional doses during stress or illness are necessary to prevent adrenal crisis.
Is there a surgical management option for Addison’s disease?
There is no specific surgical management, but surgical intervention may be needed for underlying causes such as adrenal haemorrhage or tumours.
How does Addison’s disease impact glucose regulation?
Cortisol deficiency impairs gluconeogenesis, leading to hypoglycaemia, especially during fasting or stress.
Why is hyperpigmentation a feature of Addison’s disease?
Increased ACTH levels stimulate melanocyte activity due to shared precursor molecules, leading to hyperpigmentation.
How does Addison’s disease differ from secondary adrenal insufficiency?
Secondary adrenal insufficiency is caused by pituitary or hypothalamic dysfunction, leading to low ACTH levels, while Addison’s disease involves adrenal gland dysfunction.
What lifestyle adjustments might someone with Addison’s disease need to make?
Patients need to carry a steroid emergency card, wear a medical alert bracelet, and adjust medication doses during illness or stress.
How can Addisonian crises be prevented?
By adhering to prescribed steroid replacement therapy, recognising early symptoms, and increasing steroid doses during illness or stress.
What is the role of fludrocortisone in Addison’s disease management?
Fludrocortisone replaces aldosterone, helping regulate sodium and potassium balance and maintain blood pressure.
What infections are commonly linked to the development of Addison’s disease?
Tuberculosis and fungal infections such as histoplasmosis are associated with adrenal destruction leading to Addison’s disease.
Why is an emergency injection of hydrocortisone critical in Addisonian crisis?
It rapidly restores cortisol levels, stabilising blood pressure, glucose levels, and overall metabolism during a life-threatening adrenal crisis.
