Addison’s disease, also known as primary adrenal insufficiency, can be classified based on its underlying causes. The two main classifications of Addison’s disease are:
- Autoimmune Addison’s Disease: This is the most common form of Addison’s disease, accounting for approximately 70-80% of cases. In autoimmune Addison’s disease, the body’s immune system mistakenly attacks and damages the adrenal cortex, the outer layer of the adrenal glands. This autoimmune reaction leads to decreased production of cortisol and aldosterone, resulting in adrenal insufficiency.
- Non-Autoimmune Addison’s Disease: This classification includes all cases of Addison’s disease that are not caused by autoimmune destruction of the adrenal cortex. It can be further categorized into various subtypes, including:a. Infections: Certain infections, such as tuberculosis, fungal infections (e.g., histoplasmosis, coccidioidomycosis), or HIV/AIDS, can affect the adrenal glands and lead to adrenal insufficiency.b. Adrenal Gland Damage: Trauma, bleeding into the adrenal glands (adrenal hemorrhage), tumors (e.g., metastatic cancer), or surgical removal of the adrenal glands can result in adrenal insufficiency.c. Genetic Disorders: Rare genetic disorders such as congenital adrenal hyperplasia, adrenoleukodystrophy, or familial glucocorticoid deficiency can cause adrenal insufficiency.d. Medications or Toxins: Prolonged use of medications that suppress adrenal function, such as corticosteroids, can lead to adrenal insufficiency when the medication is withdrawn or reduced. Certain toxins, such as those found in some fungal infections or certain chemicals, can also damage the adrenal glands.e. Other Causes: Rarely, other factors such as amyloidosis, metastatic cancer, or sarcoidosis can affect the adrenal glands and lead to adrenal insufficiency.
It’s important to note that autoimmune Addison’s disease is the most common form, while non-autoimmune causes are less frequent. However, the specific classification and underlying cause of Addison’s disease can vary from person to person. A thorough evaluation by healthcare professionals, including medical history, physical examination, and diagnostic tests, is necessary to determine the specific cause and appropriate management for each individual case.