Cushing's syndrome

Question 1

Cushing’s syndrome / disease

Answer 1

Cushing’s syndrome is a clinical state of increased free circulating glucocorticoid (cortisol).

Question 2

Causes

Answer 2

Can be:
 ACTH-dependent disease
 Non-ACTH-dependent disease

When investigating the cause it is essential to exclude exogenous glucocorticoids as the
cause of a “Cushingoid” appearance

Question 3

Signs and clinical features

Answer 3

Clinical features include:
 Pigmentation (only with ACTH-dependent causes)
 “Cushingoid” appearance
 Impaired glucose tolerance
 Hypokalaemia
 Hypertension

Signs include:
 moon face
 purple or red striae
 acne
 thin skin
 bruising

Question 4

Diagnosis

Answer 4

This is a two-step process, involving signs and clinical features, tests and measurements.
These include:
 Low dose dexamethasone suppression test
 24-hour urinary free cortisol measurements
 Circadian rhythm – midnight plasma or late night salivary cortisol

Question 5

Treatment

Answer 5

If caused by long term use of corticosteroids; the dose should be gradually reduced to the lowest dose that controls the condition being treated. If caused by a tumour; cortisolinhibiting medications, radiotherapy or surgery are potential options.
Cortisol-inhibiting medications include metyrapone and ketoconazole.

Question 6

controlling the symptoms of the disease; it is also used in other forms of Cushing’s syndrome to prepare the patient for surgery.

Answer 6

metyrapone - Usual dose 0.25–6 g daily, dose to be tailored to cortisol production, dose is either low, and tailored to cortisol production, or high, in which case corticosteroid replacement therapy is also need

Question 7

used under specialist supervision for treatment of endogenous Cushing’s syndrome.

Answer 7

ketoconazole - Initially 400–600 mg daily in 2–3 divided doses, increased to 800–1200 mg daily; maintenance 400–800 mg daily in 2–3 divided doses, for dose titrations in patients with established dose, adjustments in adrenal insufficiency, or concomitant corticosteroid replacement therapy, consult product literature; maximum 1200 mg per day.

Question 8

To see if you have Cushing’s you will probably be given a

Answer 8

tablet called dexamethasone. In people who do not have Cushing’s, taking this tablet will completely suppress the production of the hormone cortisol. You may also have a series of blood tests and urine tests and even saliva tests. The urine test involves collecting all the urine you pass during 24 hours (for example, between nine o’clock one morning and nine o’clock the next morning). The hospital will provide a special container for this and you will be told how to take accurate and clean samples.