Cushing's disease

Syndrome of glucocorticoid steroid excess, secondary to corticotroph adenoma of the pituitary gland. The diagnosis is confirmed with failure of cortisol suppression on a low dose dexamethasone suppression test, elevated ACTH and with an elevated midnight cortisol.

General examination

To diagnose Cushing's disease, a detailed and full general examination is mandatory in the initial assessment. 

Blood pressure

Elevated BP may not have been previously noted.

BMI

Baseline recording is useful.

Body habitus

Waist hip ratio is typically increased. The typical pattern of peripheral wasting and central obesity is commonly seen and should ideally be photographed.

Skin

To demonstrate thinned skin gently pinch the skin on the back of the hand to seek the fine wrinkling of thinned atrophic skin. Extensive bruising, for example from venepuncture, may also be present. 

Striae are common and should fade soon after forming, typically at times of rapid growth such as puberty or pregnancy. In Cushing’s, the striae remain livid - purple or red and are often extensive. 

Acanthosis nigricans is indicative of insulin resistance of any cause.

New pigmentation is suggestive of high levels of ACTH typically from an ectopic source.

Myopathy

One of the most sensitive tests is to ask the patient to squat on the floor with their heels flat on the ground. While demonstrating the same thing, ask the patient to then rise to a standing position without using their arms for support or swinging their bottom up and out first. 

More severe myopathy will be evident by asking the patient to rise from a chair without using their arms for support.

Virilisation

Examine the musculature for increased bulk in women. Examine for changes in secondary sexual characteristics, for hirsuitism and for clitoromegaly.