Cushing's Syndrome Flashcards
when does Cushing’s syndrome occur
- occurs due to long term cortisol overexposure –> hypercortisolism
- (pathological overproduction of cortisol)
give some causes of Cushing’s syndrome
exogenous:
- iatrogenic (glucocorticoid prescription)
endogenous - ACTH dependent:
- ant. pit. tumour
- ectopic tumour
endogenous - ACTH independent: CARS
C - cancer (adrenal/hypothalamic adenoma)
A - adrenal nodular hyperplasia
R - rare causes e.g. McCune-Albright syndrome
S - steroid use
describe 1° hypersecretion due to adrenal problem
- ↓CRH
- ↓ACTH
- ↑cortisol
describe 2° hypersecretion due to pituitary problem
- ↓CRH
- ↑ACTH
- ↑cortisol
describe 2° hypersecretion due to hypothalamic problem
- ↑CRH
- ↑ACTH
- ↑cortisol
when does Cushing’s disease occur
overproduction of ACTH from ant. pit. adenoma
what is the most common cause of Cushing’s
anterior pituitary adenoma (60-70% of cases)
how might a Px w/ Cushing’s syndrome present
- central obesity (deposition of fat in face and abdomen)
- thin limbs (proximal limb muscle wasting)
- moon face
- hypertension
- buffalo hump
- abdominal striae
- hyperglycaemia
- pink in face
- insomnia, depression
- thinning of skin, easy bruising
- acne (comedones)
what causes hypertension in Cushing’s syndrome
cortisol binds to aldosterone receptors causing ↑ in BP
what causes acne in Cushing’s
↑androgens
describe the effects of hypercortisolism on carb metabolism
hyperglycaemia –> ‘adrenal diabetes’
describe the effects of hypercortisolism on prot metabolism
- protein shortage –> muscle weakness
- striae
- easy bruising and thinning of skin
what are some complications of Cushing’s
- osteoporosis
- immunosuppression
- diabetes mellitus
- delayed healing of fracture/soft tissue injuries
what test can be done to confirm ant. pit. adenoma in Cushing’s
dexamethasone suppression test
- measures cortisol and ACTH
- dexamethasone normally suppresses cortisol but not in Cushing’s disease
what other investigation can be done to confirm Cushing’s
free urinary cortisol
