Cushing syndrome - exogenous

Definition

Exogenous Cushing syndrome is a form of Cushing syndrome that occurs in people taking glucocorticoid (also called corticosteroid) hormones, such as prednisone.

Alternative Names

Causes, incidence, and risk factors

Exogenous means caused by something outside the body. Exogenous Cushing syndrome occurs when a person takes synthetic glucocorticoids, such as prednisone or dexamethasone, for treatment purposes (for example, to treat asthma).

The signs and symptoms of Cushing syndrome are due to overproduction of certain hormones produced by the adrenal glands, such as cortisol.

For other causes and more information about Cushing syndrome see:

• Cushing syndrome
• Ectopic Cushing syndrome
• Cushing's syndrome caused by adrenal tumor

Symptoms

• Euphoria, unrelated to life situation
• Moon face (round, red and full)
• Buffalo hump (a collection of fat between the shoulders)
• Central obesity with an abdomen that sticks out and thin arms and legs
• Weight gain
• Weakness
• Backache
• Headache
• Acne
• Purple streaks on the skin of the abdomen, thighs, and breasts
• Frequent and easy bruising
• Mental changes
• Impotence
• Stopping of menstruation

Additional symptoms that may be associated with this disease:

• Thirst
• Increased urination

Signs and tests

In people who currently use cortisone, prednisone or other corticosteroids, the following test results may suggest exogenous Cushing syndrome:

• ACTH level, checked in the morning, may be low or undetectable
• Cortisol level, checked in the morning, may be low or undetectable
• No response to a Cosyntropin stimulation test
• Fasting glucose is sometimes higher than normal
• Serum potassium may be low
• Low bone density, as measure by dual x-ray absorptiometry (DEXA)
• High cholesterol, particularly high triglycerides and low high-density lipoprotein (HDL)

High levels of the suspected medication in the urine can be seen with a method called high performance liquid chromatography (HPLC).

Treatment

The suggested treatment is to slowly stop taking any corticosteroids. This should only be done under medical supervision. Do not stop taking any medicine without first talking to your health care provider.

In situations where the medication cannot be stopped because of the underlying disease (for example, if steroids are needed to treat severe asthma), every effort should be made to reduce the possibility of developing complications.

Glucocorticoids levels that are too high can raise blood sugar and cholesterol levels and increase bone loss.

• High blood sugar should be treated aggressively with diet, medications taken by mouth, or insulin.
• High cholesterol should be treated with diet or medications.
• Most experts recommend treating patients who will be on steroids for longer than 4-6 weeks with medication to prevent bone loss (bisphosphonates like alendronate or risedronate). This will reduce the risk of fractures.

Expectations (prognosis)

Slowly withdrawing the drug causing the condition can help reverse the effects of adrenal gland shrinkage (atrophy), although this may take as long as a year. During this time, a patient may need to restart taking their steroids in times of stress.

Complications

Cushing syndrome symptoms may cause constant discomfort.

Steroids may cause diabetes and high cholesterol levels. If left untreated, both of these complications can increase the risk of heart attacks. Untreated high blood sugar over many years can cause damage to the eyes, kidneys and nerves.

Cushing syndrome may also lead to weak bones (osteoporosis) and increase the risk of fractures

These complications can generally be prevented with proper treatment.

Calling your health care provider

Call for an appointment with your health care provider if you are taking a corticosteroid drug and you develop symptoms of Cushing syndrome.

Prevention

Awareness of the signs and symptoms of Cushing syndrome may make early treatment possible for patients who take corticosteroids. Persons using inhaled steroids can decrease their exposure to the steroids by using a “spacer,” and by rinsing their mouths after the inhalation.