Cushing's Syndrome

In a nutshell

Cortisol excess, most often from prescribed steroids, drives protein catabolism, gluconeogenesis and central fat redistribution, producing central obesity, thin bruising skin, proximal weakness and hypertension. Diagnosis confirms excess first (dexamethasone suppression), then localises the source with ACTH.

Classic presentation

Gradual central obesity, a moon face, purple striae, proximal weakness and hypertension, often with new diabetes, in a patient on long-term corticosteroids or with an endogenous ACTH- or cortisol-secreting tumour.

Key points

• 1Exogenous corticosteroid therapy is the commonest cause of Cushing's syndrome in practice: always check the drug history first.