Diagnosis of Adrenal Disorders Flashcards
How many rings are in a steroid?
4
What is hydrocortisone?
cortisol
What is cortisone?
a biologically inactive metabolite of cortisol - needs to be metabolised in the liver to be active
What are the synthetic glucocorticoids?
prednisolone and dexamethasone
What causes the hyperglycaemia in Cushing’s syndrome?
stimulation of gluconeogenesis in the liver, breakdown of protein in the muscle, lipolysis
What is Cushing’s disease?
pituitary adenoma which produces ACTH
What are the two different types of hypercortisolism?
ACTH dependent and ACTH independent
What is an ACTH dependent cause of hypercortisolism that is not Cushing’s disease?
an ectopic tumour producing ACTH e.g. in the lung
What are the ACTH independent causes of hypercortisolism?
adrenal adenoma or carcinoma, ACTH independent nodular hyperplasia, administration of glucocorticoids
What are the signs and symptoms of Cushing’s syndrome?
moon face, obesity, hypertension, menstrual disorders, hirsuitism, weakness, striae, bruisability, osteoporosis, ankle oedema, buffalo hump
Why is it important to do diagnose with biochemical tests before doing any radiological tests?
because radiology may show something that is unrelated and lead to a misdiagnosis
What are the tests for Cushing’s?
24 hour urine cortisol, diurnal cortisol variation, dexamethasone suppression test, pituitary MRI, adrenal CT
What is Addison’s disease and what are the symptoms?
chronic primary adrenocortical insufficiency due to destruction of adrenals (autoimmune)- symptoms are anorexia, nausea, vomiting, diarrhoea, weight loss, low blood pressure, tachycardia, darkening of the skin, muscle weakness, increased susceptibility to infection
What are the causes of adrenocortical insufficiency?
enzyme defect in cortisol synthesis, adrenoleukodystrophy, autoimmune adrenal destruction, infectious disease
What is the treatment for Addison’s disease?
cortisol and fludrocortisone (aldosterone analogue)
Where on the body does Addisonian pigmentation occur?
knuckles of hands, knees, gums, oral mucosa and general pigmentation
What is CAH and what are the symptoms?
defiency in the enzyme 21-hydroxylase so can’t synthesise cortisol and aldosterone which leads to over production of androgens - symptoms are premature pubic hair, hirsuitism, acne, enlargement of penis/clitoris, behavioural changes, linear growth spurt, rapid epiphyseal fusion, muscular habitus, deepening of voice
What is prednisolone?
synthetic glucocorticoid
What is dexamethasone?
synthetic glucocorticoid
What is fludrocortisone?
synthetic mineralocorticoid
What stimulates aldosterone secretion?
potassium in extracellular fluid, angiotensin II, ACTH
What is the action of aldosterone?
salt and water absorption, potassium excretion
What is Conn’s syndrome and what are the symptoms?
an adrenocortical tumour secreting aldosterone - symptoms are hypertension (due to fluid retention) and weakness (due to potassium deficiency)
What are the symptoms of aldosterone deficiency?
dehydration, postural hypotension and cardiac arrhythmias
What is pheochromocytoma and what are the symptoms?
a tumour of the adrenal medulla leading to overproduction of catecholamines - causes episodes of pallor, palpitations, hypertension, sense of doom
