ADDISON'S DISEASE

What is it?

Addison's disease is a disorder of the adrenal glands that results in an insufficient production of the cortisol hormone.

Who gets it?

It is a rare condition affecting about 1 in 100,000 people. It affects all ages and both sexes equally.

What are the symptoms?

The symptoms of adrenal insufficiency usually begin gradually. They include:

• Chronic, worsening fatigue and muscle weakness
• loss of appetite
• weight loss
• nausea, vomiting, and diarrhea
• blood pressure is low and falls further when standing, causing dizziness or fainting
• skin hyperpigmentation, or darkening
• irritability and depression
• craving of salty foods
• low blood sugar especially in children
• menstrual periods may become irregular or stop.

Symptoms of an addisonian crisis include:

• sudden penetrating pain in the lower back, abdomen, or legs
• severe vomiting and diarrhea, followed by dehydration
• low blood pressure
• loss of consciousness.

Left untreated, an addisonian crisis can be fatal.

When should I go to my GP?

If Addison's has been diagnosed and you suffer a serious infection or debilitating illness you should contact your GP immediately. Also if your weight increases progressively, your ankles swell or you suffer any of the symptoms listed above.

What tests will I have?

A diagnosis of Addison's disease is made by laboratory tests that determine whether there are sufficient levels of cortisol. The next step is to establish the cause.

ACTH stimulation test

This is the most specific test for diagnosing Addison's disease. In this test, blood and/or urine cortisol levels are measured before and after a synthetic form of ACTH is injected.

Insulin-induced hypoglycemia test

This test is used to determine how the hypothalamus and pituitary and adrenal glands respond to stress. Blood is drawn to measure the blood glucose and cortisol levels, followed by an injection of fast-acting insulin. Blood glucose and cortisol levels are measured again at 30, 45, and 90 minutes after the insulin injection.

Other tests

X-ray exams of the abdomen may be taken to check for calcium deposits in the adrenals. Calcium deposits may indicate TB. A tuberculin skin test also may be used.

CT scanning may be used giving a cross-sectional image of a body part.

What is the treatment

Treatment of Addison's disease involves replacing the hormones that the adrenal glands are not making.
Cortisol is replaced orally with hydrocortisone tablets, a synthetic glucocorticoid, taken once or twice a day.
Aldosterone is replaced with oral doses of a mineralocorticoid, called fludrocortisone acetate, which is taken once a day.

Doses will need to be increased at times of stress or infection. Occasionally at times of crisis an injection of hydrocortisone may be necessary.

Will I need long-term treatment?

You will need to take the replacement hormones indefinately. The doses will need to be reviewed regularly.

Special care must be taken during surgery and pregnancy as these put extra stresses on the body.