Autoimmune Addison disease
Autoimmune Addison disease is a disorder where the immune system attacks the adrenal glands, disrupting the production of essential hormones and affecting multiple body systems.
Description
Autoimmune Addison disease affects the function of the adrenal glands, which are small hormone-producing glands located on top of each kidney. It is classified as an autoimmune disorder because it results from a malfunctioning immune system that attacks the adrenal glands.
Common features include extreme tiredness (fatigue), nausea, decreased appetite, and weight loss. Affected individuals often have low blood pressure (hypotension), muscle cramps, and a craving for salty foods. A characteristic feature is abnormally dark areas of skin (hyperpigmentation), especially in regions of friction like armpits, elbows, and knuckles, as well as the lips and mouth lining. Women may experience a loss of underarm and pubic hair.
Other signs include low blood sugar (hypoglycemia), low sodium (hyponatremia), and high potassium (hyperkalemia). Affected individuals may also have a shortage of red blood cells (anemia) and an increase in certain white blood cells (lymphocytosis and eosinophilia).
The condition can lead to a life-threatening adrenal crisis, characterized by vomiting, abdominal pain, and severe hypotension leading to shock, often triggered by stress, surgery, or infection.
Frequency
Addison disease affects approximately 11 to 14 in 100,000 people of European descent. The autoimmune form accounts for up to 90 percent of cases in developed countries.
Causes
The cause is complex, involving a combination of environmental and genetic factors. The most commonly associated genes belong to the HLA complex, which helps the immune system distinguish the body's own proteins from foreign invaders. A specific variant, HLA-DRB1*04:04, is a well-known risk factor.
In this disease, the immune system is triggered by a normal adrenal gland protein, typically 21-hydroxylase. The resulting immune attack damages the outer layers of the adrenal glands (the adrenal cortex), preventing hormone production.
Inheritance
A predisposition to develop autoimmune Addison disease is passed through generations in families, but the specific inheritance pattern is unknown.
Other Names for This Condition
- Autoimmune Addison's disease
- Autoimmune adrenalitis
- Classic Addison disease
- Primary Addison disease