Autoimmune Addison’s Disease - An Overview

Introduction

Addison’s disease is an uncommon, chronic disorder that results from the impaired functioning of an adrenal cortex, thereby leading to a deficient production of hormones such as glucocorticoids, mineralocorticoids, and male hormones. The researchers have reported that autoimmune Addison’s disease is the most common cause of the disease in adults, accounting for more than 85 percent of cases, followed by tuberculosis infection in approximately 11 percent of patients, and the remaining four percent of patients are affected either due to vascular, malignant or hereditary forms.

What Is Autoimmune Addison's Disease?

Autoimmune Addison’s disease is an uncommon autoimmune disease that alters the function of the adrenal glands. The adrenal glands are tiny hormone-synthesizing glands on top of each renal capsule. It is subclassified as an autoimmune disease resulting from a malfunctioning immune system that invades these adrenal glands. Therefore, the production of several hormones is interrupted, affecting several body organs.

What Are the Other Synonyms of Autoimmune Addison's Disease?

• Autoimmune Addison disease.

• Autoimmune adrenalitis.

• Classic Addison’s disease.

• Primary Addison’s disease.

Who Does Addison’s Disease Affect?

All age groups are susceptible to Addison's disease, although those between the ages of 30 and 50 are most frequently affected. The risk of developing Addison's disease is significantly higher in those with autoimmune polyendocrine syndrome, a rare hereditary disorder in which your immune system unintentionally targets numerous tissues and organs. This illness typically affects your adrenal glands, parathyroid glands, and mucous membranes, though it can also impact other tissues and organs. The autoimmune (most prevalent) version of Addison's disease is more likely to occur in those with the following autoimmune diseases:

• Chronic thyroiditis (it is brought on by the immune system's attack on the thyroid gland).

• Dermatitis herpetiformis (it is a chronic illness that renders your skin covered in blisters and itchy pimples).

• Vitiligo (it is a long-term autoimmune condition that results in color loss in certain skin areas).

• Myasthenia gravis (this is a long-term autoimmune disease where antibodies obstruct nerve-muscle transmission, making the skeletal muscles feeble).

• Type I diabetes (low blood sugar level).

• Pernicious anemia (it is an autoimmune disease that is comparatively uncommon and lowers the body's ability to absorb vitamin B12 from food, leading to a B12 shortage and megaloblastic anemia).

• Graves' disease (it is an autoimmune disease that affects the thyroid gland).

What Are the Signs and Symptoms of Autoimmune Addison's Disease?

The clinical signs and symptoms of autoimmune Addison’s disease can appear at any age, but mostly, they begin to show between the third and fifth decades of life. Some of the common symptoms of the disorder include:

• Tiredness (extreme fatigue).

• Nausea and vomiting.

• Loss of appetite.

• Loss of weight.

• Low blood pressure.

• Dizziness on standing up suddenly.

• Muscle pain.

• Craving for salty food products.

• Hyperpigmentation is a characteristic feature of autoimmune Addison’s disease that is characterized by abnormally dark, blackish areas of skin, especially in areas such as the armpits, elbows, knuckles, and creases of the palm. These areas experience a lot of friction. Even the labial mucosa and the lips can turn unusually dark.

• Women might lose their pubic and underarm hair due to a hormonal imbalance. These hormones are responsible for developing secondary sexual characteristics in humans.

• Hypoglycemia (low levels of sugar) is present in the blood.

• Low levels of sodium (hyponatremia) are observed in the blood.

• High levels of potassium (hyperkalemia) are observed in the blood.

• Anemia may sometimes be seen in the affected individuals.

• An increase in the number of white blood cells, particularly eosinophils, is also seen in the blood.

• Autoimmune Addison’s disease can cause a life-threatening crisis of the adrenal glands. The condition can lead to severe nausea and vomiting, pain in the abdomen, muscle cramps in the back or legs, and extremely low blood pressure, leading to shock. Such a crisis can usually be triggered in cases of surgery, trauma, or bacterial or viral infections.

What Is the Frequency of Autoimmune Addison's Disease?

Addison's disease is found in approximately 10 to 15 people out of 100,000 people of European descent. The autoimmune form of Addison’s disease is the most frequently present form in developed countries, accounting for more than 90 percent of the disease cases.

What Are the Causes of Autoimmune Addison's Disease?

The etiology of autoimmune Addison’s disease is not completely known. A multifactorial etiology of environmental and hereditary factors plays a major role in disease pathogenesis, and multiple gene mutations are found to be responsible for developing the serious condition.

The genes also participate in the immune reactions of the body. They are related to autoimmune Addison’s disease also. Human leukocyte antigen complex genes are most commonly associated with the disease. The human leukocyte antigen complex helps differentiate between the proteins synthesized by the body and the proteins produced by foreign agents like viruses and bacteria. Various phenotypic variations are present in each human leukocyte antigen gene. This genetic arrangement allows the immune system of every individual to react differently to the different foreign proteins present. The HLA-DRB1 gene is the most common predisposing factor responsible for causing autoimmune Addison’s disease.

In autoimmune Addison’s disease, a typical adrenal gland protein called 21-hydroxylase is responsible for initiating an immune response. This adrenal gland protein is mainly responsible for producing certain hormones in the adrenal glands. The immune attack is prolonged and usually initiated by 21-hydroxylase, which leads to damage to the adrenal glands, particularly the adrenal cortex, thereby preventing the production of hormones. It is this adrenal insufficiency (a deficiency of adrenal hormones) that leads to the disruption of various functions in the body, thereby causing low blood sugar, low sodium levels in the blood, hypotension, muscular cramps, skin darkening, and other clinical features of autoimmune Addison’s disease.

How to Diagnose Autoimmune Addison's Disease?

The healthcare professional will ask about the medical history and the symptoms experienced by the patient. He will carry out a physical examination and suggest some laboratory tests to check the serum potassium and serum sodium levels. The healthcare professional may also suggest certain imaging tests to measure hormonal levels. A person may undergo any of the following tests:

• Blood Examination: This test measures cortisol, sodium, potassium, and adrenocorticotropic hormone (ACTH) levels in the blood. A blood test can also measure antibodies linked to the autoimmune Addison's disease.

• Test for ACTH Stimulation: ACTH instructs the adrenal glands to produce cortisol. This test quantifies the blood's cortisol levels before and after an injection of synthetic ACTH.

• Insulin-induced Test of Hypoglycemia: This test determines whether the pituitary gland is causing secondary adrenal insufficiency. After an insulin injection, the test measures cortisol and blood sugar levels.

• Imaging Examinations: An abdominal CT scan searches for additional problems in addition to determining the size of the adrenal glands. One can check for secondary adrenal insufficiency with a pituitary gland MRI.

How Is Autoimmune Addison's Disease Treated?

The doctor prescribes medications that will help to regulate your adrenal glands.

It is very important to follow the treatment plan suggested by your doctor. If left untreated, Addison’s disease can progress to a life-threatening condition called Addisonian crisis. In this condition, the doctor may suggest medications to treat the Addisonian crisis first. A combination of glucocorticoid medications (anti-inflammatory drugs) to improve an individual's health is generally prescribed. These medications must be taken for the rest of your life, and not a single dose can be missed. Hormone replacement therapy may also be prescribed to replace hormones that are not being produced by the adrenal glands.

What Is the Prognosis for Addison’s Disease?

For Addison's illness, there is typically a good prognosis. Individuals with Addison's disease can lead regular, healthy lives despite needing to take medication for the rest of their lives. Nonetheless, careful monitoring of these drugs' dosages is necessary to avoid over- or under-treating patients. Osteoporosis, Type 2 diabetes, and obesity may arise from overusing glucocorticoids (Hydrocortisone). Fludrocortisone overuse may result in hypertension or elevated blood pressure. One or more autoimmune conditions can occur in up to 50 percent of Addison's disease patients.

When to See a Doctor?

Consult a physician if you have any of the following typical Addison's disease symptoms:

• Darkened skin patches.

• Severe dehydration or loss of bodily water.

• Extreme exhaustion.

• Loss of weight.

• Stomach ache, vomiting, or nausea.

• Feeling dizzy or faint.

• Crave for salt.

• Joint or muscle aches.

Conclusion

Autoimmune Addison’s disease is a serious disorder affecting the functions of the adrenal glands. Individuals should seek the advice of a doctor if they are experiencing the symptoms of the disease. Regular follow-up is required to improve overall health. Always keep an emergency kit of medicines at home handy at all times. Do not take the condition lightly.