Addison’s disease is also called as chronic adrenal insufficiency, hypocortisolism or hypocorticism. It is a rare disorder where the adrenal glands are not able to produce glucocorticoids and less often mineralocorticoids in sufficient quantity. The condition was first described by Dr. Thomas Addison, a British physician.
Causes of Addison’s disease
Adrenal dysgenesis
This means adrenal glands which produce glucocorticoid are absent.
Impaired Formation of Hormone
To form cortisol, the adrenal gland requires cholesterol, which is then converted biochemically into steroid hormones. Interruptions in the delivery of cholesterol include Smith-Lemli-Opitz syndrome and abetalipoproteinemia.
Congenital adrenal hyperplasia may also cause impaired synthesis.
Medications
Medications like ketoconazole interfere with enzymes that synthesize the hormone, while others like rifampicin, phenytoin, etc increase hormonal breakdown.
Adrenal destruction
- Autoimmune adrenalitis
- Adrenoleukodystrophy (ALD)
- Metastasis
- Hemorrhage (Waterhouse-Friderichsen syndrome or antiphospholipid syndrome)
- Infection
- Amyloidosis
Symptoms and signs Of Addison’s Disease
The disease symptoms are insidious in onset and per se, the symptoms are quite non-specific. Following symptoms can be noted with this condition.
- Fatigue
- Lightheadedness upon standing or while upright
- Muscle weakness
- Weight loss
- Anxiety
- Nausea, vomiting, diarrhea
- Headache, sweating
- Changes in mood and personality
- Vague joint and muscle pains
- Marked cravings for salt or salty foods [Due to loss of salt in urine]
- Darkening of the skin [Due to hyperpigmentation]
- Orthostatic hypotension [Low blood pressure that falls further when standing]
Lab Studies
Routine lab investigations may show
- Hypocalcemia or low calcium level
- Hypoglycemia or low blood sugar level
- Hyponatremia or low blood sodium levels
- Hyperkalemia or raised blood potassium levels
- Eosinophilia and lymphocytosis
- Metabolic acidosis (increased blood acidity), also due to loss of the hormone aldosterone
- Renin and adrenocorticotropic hormone levels
ACTH stimulation test
Low adrenal hormone levels even after appropriate stimulation with synthetic pituitary ACTH hormone.
Ultrasound, computed tomography or magnetic resonance imaging are other tests used in making a diagnosis.
Treatment of Addison’s Disease
Treatment aims at replacing the missing cortisol. Hydrocortisone or prednisone tablets are commonly used and are continued for life. In addition, many patients require fludrocortisone as a replacement for the missing aldosterone.
What Is Addisonian Crisis?
Addisonian crisis is also called adrenal crisis. It is a constellation of symptoms that indicate severe adrenal insufficiency.
It may occur in either previously undiagnosed Addison’s disease due to a disease process suddenly affecting adrenal function. It may also occur due to an intercurrent problem like infection or trauma in the setting of known Addison’s disease.
The situation may also develop in those on long-term oral glucocorticoids who have suddenly stopped taking their medication.
Addisonian crisis is also a concern in the setting of myxedema coma. Thyroxine given in that setting without glucocorticoids may precipitate a crisis.
Untreated, an Addisonian crisis can be fatal.
It is a medical emergency, usually requiring hospitalization.
Following symptoms would suggest Addisonian crisis
- Sudden penetrating pain in the legs, lower back or abdomen
- Severe vomiting and diarrhea, resulting in dehydration
- Low blood pressure
- Syncope (loss of consciousness)
- Hypoglycemia
- Confusion, psychosis, slurred speech
- Severe lethargy
- Hyperkalemia
- Hypercalcaemia
- Convulsions
- Fever
Prevention
It is recommended that a person with adrenal insufficiency should always carry identification stating their condition in case of an emergency.
The card should alert emergency personnel about the need to inject 100 mg of cortisol if its bearer is found severely injured or unable to answer questions. The card should also include the doctor’s name and telephone number and the name and telephone number of the nearest relative to be notified.
When traveling, a needle, syringe, and an injectable form of cortisol should be carried for emergencies. A person with Addison’s disease also should know how to increase medication during periods of stress or mild upper respiratory infections. Immediate medical attention is needed when severe infections, vomiting, or diarrhea occur, as these conditions can precipitate an Addisonian crisis.
A patient who is vomiting may require injections of hydrocortisone, since oral hydrocortisone supplements cannot be adequately metabolised.