What is the most common cause of primary adrenal insufficiency in developed countries?

• A. Tuberculosis
• B. Autoimmune adrenalitis
• C. Adrenal hemorrhage
• D. Familial adrenal cortical hyperplasia

Answer: (D)

Autoimmune destruction of the adrenal cortex is the most common cause of primary adrenal insufficiency in developed countries. In these regions, autoimmune adrenalitis accounts for the majority of cases because TB-caused Addison’s disease is now relatively rare thanks to better TB control and vaccination. Autoimmune destruction gradually reduces cortisol and often aldosterone, leading to the classic symptoms of adrenal failure.

Adrenal hemorrhage is a less frequent cause and typically presents acutely, often in the context of sepsis, coagulopathy, or trauma, rather than as a gradual autoimmune process. A condition like familial adrenal cortical hyperplasia is rare and does not represent the typical mechanism underlying most cases of Addison’s disease in well-resourced countries.