Excess circulating glucocorticoids.
In Cushing's disease this is caused by excess pituitary ACTH production. In adrenal Cushing's syndrome this is usually caused by gain of function variants of PRKACA. Ectopic ACTH can be produced by tumours.
- Moon face
- Central obesity
- Hirsutism and menstrual disorder
- Osteoporosis with backache, vertebral collapse
- Sodium retention
- Potassium loss
- Hypokalaemic alkalosis
Low dose dexamethasone suppression test. ( Dexamethasone 1mg orally @ midnight, serum cortisol @ 09:00. If <50mmol/L excludes diagnosis)
High dose dexamethasone suppression test
Stop or minimize exogenous steroids