Addison's Disease

Addison’s disease, also called hypocortisolism or adrenal insufficiency, occurs when the body is not producing adequate cortisol and sometimes aldosterone. Cortisol is produced by the adrenal glands, also known as the suprarenal gland, situated over the kidneys. The proper functioning of those tiny triangle-shaped glands is essential and controlled by higher centers in the brain. The adrenal gland is the endocrine gland, and it releases hormones in the blood. In Addison’s disease, the outer part of the adrenal gland, called the cortex, is damaged, failing Cortisol, aldosterone, androgens, and estrogen production. Some of the vital functions of cortisol are it helps control blood sugar levels, decreases inflammation after cellular injury, and assists in metabolism and memory control. Cortisol is also called a stress hormone and is actively released when there is any stress, flight, or fight situation in the body. For example, When the body is under stress, the hypothalamus, the high center of the brain, signals to the pituitary gland, which then enables the adrenal cortex to secret cortisol in the bloodstream, which increases the heart rate, activates the glucose production to be used by the active muscles, etc. and deactivates the other mechanisms of the body which are not needed in that immediate situation. Addison's disease, in its initial course, is unnoticed. It’s only alarming when the symptoms worsen and need immediate attention and a management plan.

Factors that lead to adrenal Insufficiency include;

• Excess glucocorticoid usage.
• Adrenal gland Tumor or Cancer.
• Trauma to the head
• Pituitary tumor
• Use of anticoagulants medications
• Severe infections

There are two main categories of Addison's disease depending on the origin of the problem;

Primary adrenal insufficiency (Autoimmune disorder)

In primary adrenal insufficiency, your body’s immune system reacts abnormally against adrenal glands, damaging them and resulting in the complete cessation of cortisol production.

Secondary Adrenal insufficiency ( Acquired)

This is due to the inability of the Pituitary gland to produce Adrenocorticotropic hormone (ACTH), which sends a signal to the adrenal gland to secrete cortisol or adrenaline. The pituitary gland is a pea-sized gland located at the base of the brain. This pathology in pituitary gland regulation could be due to tumors, certain medications, genetics, or brain trauma.

Addison’s disease is rare. In the USA, Addison's disease affects 40-60 people per 1 million population. There is no race predilection for Addison's disease. Primary Addison’s insufficiency is more common in children and Females. Adults of 30-50 years are most commonly presented to the clinics with this disease.

RISK FACTORS

The following factors may increase your chances of having the disease;

• Autoimmune diseases like Graves’ disease or type 1 diabetes.
• Resection of part of the adrenal gland.
• Family history
• Chronic diseases like tuberculosis.
• Cancer
• Use of Blood thinners

Since the adrenal gland affects many organ systems, there is a wide range of signs and symptoms.

• Dizzy spells.
• Vomiting
• Nausea.
• Dark skin discoloration
• Muscle weakness.
• Lethargy.
• Weight loss.
• Decreased appetite.
• Low blood sugar levels.
• Salt hunger.
• Mount ulcers
• Lack of energy.
• Agitation
• Depression.
• Sleep disturbances.
• Joint pain.
• Hair loss.
• Irritability.
• Neuropsychiatric symptoms like mood swings
• Sexual dysfunction
• Abdominal pain
• Irregular menstruation
• Heat or cold intolerance

ADDISONIAN CRISIS: also called an acute adrenal crisis, is a life-threatening emergency characterized by sudden hypoglycemia (low blood sugar), hypotension (low blood pressure), hyponatremia ( low blood sodium), and hyperkalemia (high blood potassium). Initially patient feels a loss of appetite, nausea, vomiting, abdominal pain, and diarrhea. But as the condition deteriorates, fevers, chills, and sweating become prominent, followed by loss of consciousness, Psychosis, Mumble speech, Palpitations, and Convulsions. It is triggered by sudden emotional trauma, Severe dehydration, Severe allergies, Pregnancy complications, or Sudden steroid stopping. It is managed in the emergency department with immediate administration of fluids, and corticosteroids and maintaining optimum blood sugar levels, blood pressure, and electrolytes. 

It is challenging to diagnose adrenal insufficiency in the early stages of the disease because symptoms don’t appear suddenly. Good history and physical examination will help. On examination, dark patches on the skin can be a quality clue for Addison's disease. Blood testing is crucial to diagnose the disease itself by identifying the antibodies, and it can also help determine the underlying cause.

Some necessary tests include:

1)ACTH Stimulation test(Also called Synacthen stimulation test): This test is mainly used to diagnose adrenal Inadequacy. In this test, laboratory-produced ACTH is injected. Then Blood samples are drawn at different time intervals for testing. Normally, if levels of ACTH are increased in the blood, in turn, there are increased cortisol levels as activation of alarm mechanism in the body, but in Addison’s disease, the cortical levels are not raised or have minimal rise. ACTH stimulation test is not helpful in secondary adrenal insufficiency as the size of adrenal glands is still normal to respond well to any insignificant event occurring in the body.

2) Insulin tolerance test (ITT): This test is performed when the ACTH stimulation test is not clear enough to make a diagnosis. In this test, insulin is injected into the body, which, in response, lowers glucose levels in the blood. This hypoglycemic state provokes the pituitary gland to make a lot of ACTH. If the levels of ACTH did not rise to the expected levels, cortisol levels would not rise as well. In turn, it confirms the diagnosis of adrenal insufficiency; this test is fairly reliable to diagnose secondary adrenal insufficiency.

3) Cortocotrophin-releasing hormone stimulation test (CRH): This test is also performed when the Adrenocorticotrophin hormone(ACTH) stimulation test is unclear. It is most effective to diagnose secondary adrenal insufficiency in this test. CRH is injected, and blood is drawn at multiple time intervals to test levels of ACTH.

4) Antibody blood test( Autoimmune Addison's disease): This test reveals certain antibodies in the blood, diagnosing autoimmune Addison’s disease.

5) CT scan: CT scan of the abdomen helps find structural changes in adrenal glands, which is commonly done in Autoimmune Addison’s disease.

6) MRI: This is done to identify changes in the pituitary gland and hypothalamus.

7) Thyroid function test(TFT)

Addison’s disease is a permanent, incurable disease, but hormone replacement therapy alters the symptoms associated with the disease tremendously. The management of temporary adrenal insufficiency depends on the underlying cause. If it is due to any infectious disease, like tuberculosis, treating the infection will wave the disease. Similarly, If it is due to diabetes or underactive thyroid, treating these will also cure Addison's disease. But if it is due to a bizarre immune system, then a permanent cure is not possible. Treatment for such entities requires a lifetime management plan. It includes.

1. Lifetime corticosteroid replacement therapy.
2. Hydrocortisone as a replacement for cortisol.
3. Prednisolone or dexamethasone is uncommonly used.
4. Fludrocortisone is used as an alternative to Aldosterone.
5. In an adrenal crisis, hydrocortisone is given intravenously or intramuscularly as soon as possible. For low blood pressure, Intravenous saline is given.

People who have Addison’s disease can live normal, healthy life only by taking medication for their whole life. Usually, failure or delay in diagnosing results in morbidness and death. Even after diagnosis, the chances of dying are twice more than the general population. This might be due to a failure in instituting adequate mineralocorticoid and glucocorticoid replacement.

Regular doctor checkups and blood testing are key milestones to stop the aggravation of the disease at any stage of life and prevent complications or Addisonian crisis. 

The following measures should be taken to cope with the illness;

• Try to learn about your disease as much as possible
• One must take medicines and hormones regularly.
• A balanced diet replacing the deficient nutrients should be taken after being advised by a nutritionist and a doctor.
• One must remain active and perform some form of exercise.
• Be around your friends and family members to feel supported

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 14, 2023.

Reference

https://www.mayoclinic.org/diseases-conditions/addisons-disease/symptoms-causes/syc-20350293

https://www.thieme-connect.com/products/ejournals/html/10.1055/a-0804-2715