Addison's disease is a disorder of the endocrine system in which all three classes of adrenal corticosteroids (glucocorticoids, mineralcorticoids, and androgens) are reduced. This leads to adrenocortical insufficiency.
The most common cause of Addison's disease is an autoimmune response. Adrenal tissue is destroyed by antibodies against the body's own adrenal cortex. Often, other endocrine conditions are present and in this case Addison's disease is considered a component of the polyendocrine deficiency syndrome.
Other causes of Addison's disease include infarction, fungal infections, AIDS, and metastatic cancer. Iatrogenic (caused by medical intervention) Addison's disease may be due to adrenal hemorrhage, often related to anticoagulant therapy, antineoplastic chemotherapy, ketoconazole (Nizoral) therapy for AIDS, or removal of both adrenal glands (bilateral adrenalectomy).
Because the manifestations of Addison's disease tend to not become evident until 90% of the adrenal cortex has been destroyed, the disease is often diagnosed when it's already advanced. Addison's disease symptoms have a very insidous (slow) onset and include primarily:
- progressive weakness
- skin hyperpigmentation in sun-exposed areas of the body, at pressure points, over joins, and in creases, especially palmar creases.