Adrenal disorders
Adrenal insufficiency-- Adrenal insufficiency illustrates a state in which the adrenal glands fall short in producing adequate hormone levels in any given situation.
Adrenal insufficiency can be categorized as primary or secondary. Primary adrenal insufficiency occurs when the adrenal gland itself is not functioning properly resulting in diminished levels of both aldosterone and cortisol. Secondary adrenal insufficiency stems from complications linking to the pituitary gland
Addison's disease
A rare disorder of the endocrine system which culminates in the body not producing satisfactory amounts of specific adrenal hormones. It is also known as Adrenocortical Hypofunction, Adrenal Insufficiency, and Chronic Adrenocortical Insufficiency.
CAUSES
- The adrenal glands fail to form properly. This includes congenital adrenal hypoplasia and mutations of steroidogenic factor 1 (SF-1).
- Damage of the adrenal gland. Deficiency grows after nearly absolute functional destruction (90%) of the cortex. In developed countries, at least 70% of instances are due to autoimmune disease (major auto-antibody is to the adrenal enzyme, 21-hydroxylase). About half of patients have linked 'poly glandular' autoimmune disease or as part of a polyglandular syndrome. Infections, for the most part tuberculosis accounts for numerous cases in the developing world. Other reasons are amyloidosis, metastatic disease, adrenoleukodystrophy or trauma.
- The gland fails to produce steroids. The Smith-Lemli-Opitz syndrome, Mitochondrial disorders, and defective cholesterol metabolism are some of the environments which may produce weakened steroidogenesis.
- drug-induced acceleration of hepatic metabolism of cortisol may also cause adrenal insufficiency particularly in those with an inadequate adrenal reserve. Drugs that create this effect include rifampicin, phenytoin, and barbiturates.
DIAGNOSIS & SYMPTOMS
Diagnosis
A person with a medical history of the symptoms of Addison’s disease, particularly hyperpigmentation of the skin or gums, is often enough to stir suspicion, setting off the appropriate tests.
However, the first real clue is often from the abnormal results of customary tests done in a hospital or doctor's office. These may consist of a low blood level of sodium, a high blood level of potassium, unexpected changes on an EKG or chest x-ray, and a change in the ratio of certain white blood cells.
An authoritative diagnosis of Addison's disease entails definitive tests. These will measure the quantity of aldosterone and cortisol in the urine and blood. This will also record a lack of the normal rise in the levels of these two hormones after giving out of ACTH by injection. An elevated blood level of ACTH should also be discovered. If the patient is extremely sick and Addison's disease is assumed, treatment can commence even as the diagnostic tests are being done. Once the diagnosis of Addison's disease is determined, an effort should be made to find the cause by testing for tuberculosis and other infections through x-rays and skin tests.
Symptoms
Addison's disease usually develops gradually (over several months), and symptoms may not be noticed until some taxing illness or situation crops up. Familiar symptoms are:
- Chronic fatigue that increasingly worsens
- Craving for salt and salty foods
- Darkening of the skin known as melasma suprarenale
- Depression
- For women, menstrual period that becomes erratic or stops
- Hypoglycemia or low blood sugar
- Increased quantity of eosinophils
- Irritability
- Low blood pressure that drops further when standing (orthostatic hypotension)
- Mouth lesions on the inside of a cheek (buccal mucosa)
- Muscle weakness
- Nausea, vomiting, or diarrhea
- Numbness of the extremities, occasionally with paralysis, due to potassium excess
- Polyuria or the flood of a sizeable volume of urine in a given period
- Tetany (mostly after drinking milk) due to phosphate excess
- Weight loss and loss of appetite
TESTS & TREATMENT
ACTH Stimulation Test
This is the most exact test for diagnosing Addison's disease. In this test, urine cortisol, blood cortisol, or both are calculated before and after a synthetic type of ACTH is given by injection. In this test, computation of cortisol in blood is repeated 30 to 60 minutes following an intravenous ACTH injection. The normal response after an injection of ACTH is an increase in blood and urine cortisol levels. Patients with either type of adrenal insufficiency react poorly or do not react at all.
CRH Stimulation Test
When the reaction to the quick ACTH test is abnormal, a "long" CRH stimulation test is called for to verify the cause of adrenal insufficiency. Synthetic CRH is injected intravenously and blood cortisol is calculated before and 30, 60, 90, and 120 minutes following the injection. Patients with primary adrenal insufficiency have high ACTHs but do not yield cortisol. Patients with secondary adrenal insufficiency have poor cortisol reactions but absent or delayed ACTH reactions. Absent ACTH response directs to the pituitary as the cause while a delayed ACTH response directs to the hypothalamus.
TREATMENT
Management of Addison's disease entails substituting the hormones that the adrenal glands are not producing. Cortisol is replaced orally with hydrocortisone tablets, a synthetic glucocorticoid, taken once or twice a day. If aldosterone is also scarce, it is replaced with oral doses of a mineralocorticoid called fludrocortisone acetate (Florinef), which is taken once a day. Patients receiving aldosterone replacement therapy are as a rule advised by a doctor to increase their salt intake. Because patients with secondary adrenal deficiency normally continue aldosterone production, they do not need aldosterone replacement therapy. The doses of each of these medicines are regulated to meet the needs of individual patients.
During an Addisonian episode, low blood glucose, high levels of potassium, and low blood pressure can be life threatening. Standard treatment involves intravenous injections of saline (salt water), dextrose (sugar) and hydrocortisone. This therapy usually brings swift improvement. When the patient can take fluids and medications orally, the quantity of hydrocortisone is reduced until a maintenance dose is reached.
COMPLICATIONS
Complications of glucocorticoid therapy are uncommon in the dosage used in the treatment of Addison’s disease.
Complications of mineralocorticoid therapy happen more often and include oedema (swelling of the extremities), heart enlargement, low potassium, and even congestive cardiac failure due to salt retention.
PREVENTIONS
There are no procedures for preventing Addison's disease. If a person is at risk for Addison's disease, he or she should consult the doctor about how to identify and manage the symptoms.
INCIDENCE AND STATISTICS
Addison's disease affects about 1 in 100,000 people, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
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