Addison's Disease Flashcards
What is Addison’s disease?
Autoimmune destruction of the adrenal glands
What % of hypoadrenalism cases are due to Addison’s disease?
80%
What are some other causes of hypoadrenalism?
-
Primary causes
- TB
- Metastases
- Meningococcal septicaemia
- HIV
- Antiphospholipid syndrome
-
Secondary causes
- Pituitary disorders (e.g. tumours, irradiation, infiltration)
- Exogenous glucocorticoid therapy
What are the clinical features of Addison’s disease?
- Lethargy, weakness, anorexia, nausea & vomiting, weight loss, ‘salt-craving’
- Hyperpigmentation (especially palmar creases)
- Vitiligo
- Loss of pubic hair in women
- Hypotension
- Crisis: collapse, shock, pyrexia
What adrenal autoantibodies might be seen in Addison’s disease?
Anti-21-hydroxylase
What test is done to investigate for Addison’s disease?
Tell me about it
ACTH Stimulation Test (Short synacthen test)
Plasma cortisol is measured before and 30 minutes after giving synacthen.
What electrolyte abnormalities might you see in Addison’s disease?
- Hyperkalaemia
- Hyponatraemia
- Hypoglycaemia
- Metabolic acidosis
In what % will you see electrolyte abnormalities?
30%
If a short synacthen test is unavailable, what test is useful and how do you interpret it?
9am serum cortisol test
- > 500 nmol/l makes Addison’s very unlikely
- < 100 nmol/l is definitely abnormal
- 100-500 nmol/l should prompt a ACTH stimulation test to be performed
What are patients with Addison’s disease given?
Hydrocortisone & Fludrocortisone
(Hydrocortisone given in 2 to 3 divided doses. 20-30mg daily with most given in the morning)
What education should you give the newly diagnosed addison’s disease patient?
- Emphasise the importance of not missing glucocorticoid doses
- Consider MedicAlert bracelets and steroid cards
- Discuss how to adjust the glucocorticoid dose during an intercurrent illness
Roughly, what should be done when someone with Addison’s disease becomes unwell?
They should have their glucocorticoid dose doubled.
