Cushing's Syndrome Flashcards
What is Cushing’s syndrome?
Cushing’s syndrome is a condition caused by prolonged exposure to excessive cortisol levels, either endogenous or exogenous.
What are the main symptoms of Cushing’s syndrome?
Symptoms include weight gain, central obesity, moon face, buffalo hump, skin thinning, easy bruising, muscle weakness, and hypertension.
What is the most common cause of Cushing’s syndrome?
Exogenous steroid use is the most common cause.
What is the difference between Cushing’s syndrome and Cushing’s disease?
Cushing’s disease refers to Cushing’s syndrome specifically caused by a pituitary adenoma secreting excess ACTH.
What are the endogenous causes of Cushing’s syndrome?
Endogenous causes include pituitary adenomas (Cushing’s disease), adrenal tumours, and ectopic ACTH secretion.
What is the pathophysiology of Cushing’s syndrome?
Excess cortisol disrupts normal metabolic, immune, and inflammatory responses, leading to symptoms like hyperglycaemia, hypertension, and immunosuppression.
What are the classic facial features of Cushing’s syndrome?
Moon face (round, full face) and facial plethora (redness).
What are the skin changes associated with Cushing’s syndrome?
Thin skin, easy bruising, purple striae, and poor wound healing.
What are the common metabolic complications of Cushing’s syndrome?
Hyperglycaemia, insulin resistance, dyslipidaemia, and osteoporosis.
How does Cushing’s syndrome affect blood pressure?
It often causes hypertension due to cortisol’s mineralocorticoid effects.
What are the main risk factors for developing Cushing’s syndrome?
Long-term steroid use, adrenal tumours, pituitary adenomas, and ectopic ACTH-producing tumours.
What is the gold standard test for diagnosing Cushing’s syndrome?
The 24-hour urinary free cortisol test is considered the gold standard for diagnosing hypercortisolism.
What is the role of the dexamethasone suppression test in Cushing’s syndrome?
It assesses the ability of dexamethasone to suppress cortisol production. Lack of suppression indicates Cushing’s syndrome.
What are the typical cortisol levels in Cushing’s syndrome?
Elevated cortisol levels that do not follow the normal diurnal variation.
How can the cause of Cushing’s syndrome be differentiated?
ACTH levels help differentiate ACTH-dependent (pituitary/ectopic) from ACTH-independent (adrenal) causes. Imaging studies further localise the cause.
What are the common differential diagnoses for Cushing’s syndrome?
Obesity, metabolic syndrome, chronic stress, and pseudo-Cushing’s syndrome (e.g., alcohol misuse or depression).
What imaging studies are used to investigate Cushing’s syndrome?
MRI for pituitary adenomas, CT or MRI for adrenal tumours, and CT for ectopic ACTH-producing tumours.
How is exogenous Cushing’s syndrome managed?
Gradual tapering of corticosteroids under medical supervision to allow recovery of the hypothalamic-pituitary-adrenal axis.
What is the management for Cushing’s disease?
Surgical resection of the pituitary adenoma (transsphenoidal surgery) is the first-line treatment.
How are adrenal tumours causing Cushing’s syndrome managed?
Adrenalectomy is the treatment of choice for adrenal tumours.
What are the complications of untreated Cushing’s syndrome?
Cardiovascular disease, diabetes, osteoporosis, infections, and psychiatric disorders such as depression or anxiety.
How does Cushing’s syndrome affect bone health?
Cortisol excess leads to reduced bone formation and increased bone resorption, causing osteoporosis and an increased risk of fractures.
What lifestyle advice should be given to patients with Cushing’s syndrome?
Maintain a healthy diet, engage in weight-bearing exercises, monitor for infections, and manage cardiovascular risk factors.
What medications are used for medical management of Cushing’s syndrome?
Medications include metyrapone, ketoconazole, and mitotane, which reduce cortisol production, often used when surgery is not an option.
