Addison's disease Flashcards
what is Addisons disease
primary adrenal insufficiency
what hormones are affected in Addisons
cortisol and aldosterone
what part of the adrenal glands are destructed in Addisons disease
the adrenal cortex layers; zona fasciculata (cortisol) and zona glomerulosa (aldosterone)
what is the difference between Addisons and secondary adrenal insufficiency
Addisons is where there is destruction of about 90% of the adrenal glands so they are unable to produce steroid hormones.
Secondary adrenal insufficiency is due to hypothalamic or pituitary involvement; decreased ACTH release so decreased activation of adrenals to release hormones
two presentations
acute (addisonian crisis) and chronic
aetiology
autoimmune, tuberculosis or metastasis (rarer)
risk factors
female sex, infiltrating diseases such as TB
how does Addisons disease present
postural hypotension, hypoglycaemia, weight loss, anorexia, weakness, hyperpigmentation, fatigue, nausea and vomiting
why do Addisons patient present with hyperpigmentation
increased POMC, increased ACTH and MSH
REFER TO HPG AXIS and NEGATIVE FEEDBACK
how can you tell if a patient is in addisonian crisis
confusion, reduced consciousness, delirium, hypotensive shock, tachycardia, pale, cold and clammy, oliguria
investigations
to confirm a diagnosis of Addisons; 9AM cortisol test,
serum electrolytes, blood urea, FBC
9 am cortisol test results
Addisons; less than 100nmol/L
non Addisons; more than 550 nmol/L
serum electrolytes in Addisons
high potassium, low sodium and RARELY high calcium
blood urea in Addisons
high
FBC findings in Addisons
anaemia and eosinophilia
