Addison's disease is a chronic adrenal disorder. The body does not produce enough cortisol which affects blood pressure and other body systems. There is no cure but symptoms can be controlled with proper medication.
Definition & Facts
Addison's disease is a rare hormonal imbalance that affects roughly 1 in 100,000 people. Set above each kidney is a small adrenal gland. In a healthy person these two glands produce several hormones that regulate a number of body functions.
In most cases of Addison's disease the glands are not producing cortisol. More rare is an imbalance of the hormone aldosterone. These two hormones affect nearly every system in the body. They help maintain blood pressure, regulate kidney function, control the immune system, and even balance insulin. Doctors suspect hundreds of other functions.
Symptoms & Complaints
Skin changes are very common in Addison's disease sufferers. Hyperpigmentation, or a dark tan look, can cover both hidden and commonly uncovered parts of the body. The tanning effect is most easily seen in scar tissue, joints, and pressure points. Commonly darkened are the knees and toes or the knuckles and elbows. The mucous membranes, lips. and skin folds will also darken as the illness progresses.
The affected can become moody or irritable. Depression is common. There is a strong craving for salty foods due to salt loss. Woman may stop menstruation. Children in particular can experience hypoglycemia or low blood sugar. Since symptoms are slow to develop they are often ignored for years.
A severe illness or injury can trigger what is known as an acute adrenal insufficiency, or Addisonian crisis. This potentially deadly event is characterized by strong and sudden stabbing pains in the lower back, legs, and abdomen. There is also vomiting and diarrhea with low blood pressure and fainting. If untreated, the attack is often fatal.
The most common cause of Addison's disease is the slow destruction of the adrenal cortex by the body's own immune system. This is caused by an existing autoimmune disease in 70 percent of cases. Adrenal insufficiency will begin to occur when 90 percent of the tissue is destroyed. Tuberculosis accounts for another 20 percent of primary adrenal insufficiency.
Secondary adrenal insufficiency can be caused by the surgical removal of benign pituitary gland tumors. Infections or tumors in the region of the pituitary gland can also cause this disorder. Long term use of some glucocorticoid hormone therapies can also cause temporary secondary adrenal insufficiency.
Diagnosis & Tests
Early diagnosis is difficult and rare. Often a doctor will notice darkened skin spots and will check the medical history before ordering laboratory work done to diagnose this rare illness. Routine blood tests for sodium, white blood cells, and potassium can point towards Addison's disease in many cases.
The most common and most accurate test done today is to test hormone levels in urine or blood before and after administering ACTH. ACTH is a hormone in the brain. When it is activated, it will increase the levels of cortisol that are released by the adrenal glands. In the so-called short form of the test, blood is first tested and synthetic ACTH is injected into the patient. After an hour, the cortisol level is tested again. If the patient's body does not raise the levels of cortisol, the long form of the test is given.
This test will further pinpoint the cause of the abnormal cortisol reaction. Injections of ACTH are given over a 72 hour period. Those with primary adrenal insufficiency will not produce any cortisol. Those with secondary adrenal insufficiency will produce cortisol after two or three days.
Treatment & Therapy
Treatment is fairly straight forward. The hormones that the body is not producing are replaced with orally administered medication. Cortisol is replaced with a synthetic glucocorticoid called hydrocortisone. These tablets are taken once or twice daily by most patients.
If the treatment requires aldosterone it will be given in the form of a mineralocorticoid called fludrocortisone acetate once daily. Those who need flodrocortisone acetate are often instructed to increase salt consumption as well. Normally only primary adrenal insufficiency requires aldosterone replacement therapy.
If the disease has not been diagnosed and an Addisonian crisis is suspected, or if it is known that the patient is in crisis then fast treatments with hydrocortisone, saline solution, and sugar are administered. These treatments are necessary to correct the low blood pressure, low blood sugar, and the dangerous levels of potassium in the body. It is fast acting and life saving.
Emergency treatment is followed with corrective doses of the needed hormones. Pregnancy can bring about a need to change how the doses are administered. A pregnant woman cannot risk the loss of required medication to morning sickness or indigestion. Injections of the required hormones are used to simplify treatment. Delivery sees a gradual tapering of injections and renewed use of oral medication. Surgery is handled in much the same way. Injections of hydrocortisone and saline are used before and after surgery.
Prevention & Prophylaxis