Addison's Disease

What is Addison's Disease?

Definition:
Addison's disease is a hormone deficiency caused by damage to the outer layer of the adrenal gland (adrenal cortex).

Alternative Names: Adrenocortical hypofunction; Chronic adrenocortical insufficiency; Adrenal insufficiency

Causes, incidence, and risk factors:
The adrenal glands are small hormone-secreting organs located on top of each kidney. They consist of the outer portion (called the cortex) and the inner portion (called the medulla). The cortex produces 3 types of hormones: sex hormones, glucocorticoid hormones, and mineralocorticoid hormones.

• The sex hormones, androgens (male) and estrogens (female) affect sexual development and reproduction.
• The glucocorticoid hormones (such as cortisol) maintain glucose (sugar) regulation, suppress the immune response, and help the body respond to stress.
• The mineralocorticoid hormones (such as aldosterone) regulate sodium and potassium balance.

Addison's disease results from damage to the adrenal cortex, which causes decreased production of adrenocortical hormones. This damage may be caused by the following:

• The immune system mistakenly attacking the gland (autoimmune disease)
• Infections such as tuberculosis, HIV, or fungal infections
• Hemorrhage, blood loss
• Tumors
• Use of blood-thinning drugs (anticoagulants)

Risk factors for the autoimmune type of Addison's disease include other autoimmune diseases:

• Type I diabetes
• Hypoparathyroidism
• Hypopituitarism
• Pernicious anemia
• Testicular dysfunction
• Graves' disease
• Chronic thyroiditis
• Candidiasis
• Dermatis herpetiformis
• Vitiligo
• Myasthenia gravis
• These may be caused by certain genetic defects.

Symptoms:

• Extreme weakness
• Fatigue
• Unintentional weight loss
• Nausea and vomiting
• Chronic diarrhea
• Loss of appetite
• Darkening of the skin - patchy skin color
  • Unnaturally dark color in some locations
  • Paleness may also occur
• Mouth lesions on the inside of a cheek (buccal mucosa) - pigmentation
• Slow, sluggish, lethargic movement
• Changes in the blood pressure or heart rate
• Salt craving

Signs and tests:

• Blood pressure is low.
• Cortisol level is low.
• Serum sodium is low.
• A potassium test may show increased potassium.
• An abdominal x-ray may show adrenal calcification.
• An abdominal CT scan may show adrenal calcification, enlargement or atrophy.

This disease may also alter the results of the following tests:

• Renin
• Potassium test
• Cortisol, urine
• CO2
• Aldosterone
• ACTH
• 24 hour urinary aldosterone excretion rate
• 17-ketosteroids
• 17-hydroxycorticosteroids
• Cortrosyn stimulation test
• Blood eosinophil count (a special white blood cell)

Treatment:
Replacement therapy with corticosteroids will control the symptoms of this disease. However, these drugs must usually be continued for life. Usually a combination of glucocorticoids (cortisone or hydrocortisone) and mineralocorticoids (fludrocortisone) are given.

Medication may need to be increased during times of stress, infection, or injury.

Adrenal crisis is an extreme manifestation of symptoms of adrenal insufficiency brought on by physical stress. Hydrocortisone must be injected immediately to sustain life. Supportive treatment for low blood pressure is usually necessary as well.

Some people with Addison's disease are taught to give themselves an emergency injection of hydrocortisone during stressful situations. It is important for the individual with Addison's disease to always carry a medical identification card that states the type of medication and the proper dose needed in case of an emergency.

Never skip doses of medication for this condition, as life-threatening reactions may occur. If unable to retain medication due to vomiting, notify your health care provider, go to the emergency room, or call the local emergency number (such as 911) immediately.

Also report sudden weight gain or fluid retention to the health care provider.

Support Groups:

Expectations (prognosis):
With adequate replacement therapy, most people with Addison's disease are able to lead normal lives.

Complications:
Complications may result from the following associated illnesses:

• Diabetes
• Thyrotoxicosis
• Hashimoto's thyroiditis
• Hypoparathyroidism
• Pernicious anemia
• Ovarian hypofunction or testicular failure

Calling your health care provider:
Call your health care provider if Addison's disease has been diagnosed and stress such as infection, injury, trauma, or dehydration occurs. Medication adjustment may be indicated.

Call your provider if weight increases progressively, the ankles begin to swell, or other new symptoms develop.

If symptoms of adrenal crisis (low blood pressure, diminished consciousness, difficulty breathing, abdominal pain) occur, give an emergency injection of prescribed medication as instructed or -- if this is not available -- go to the emergency room or call 911.