What condition is associated with skin hyperpigmentation due to primary adrenocortical insufficiency?

Primary adrenocortical insufficiency, commonly known as Addison's disease, leads to a deficiency in the production of corticosteroids, particularly cortisol and aldosterone. One of the hallmark features of Addison's disease is skin hyperpigmentation, which occurs due to elevated levels of adrenocorticotropic hormone (ACTH).

In Addison's disease, the adrenal glands are unable to produce adequate cortisol levels. In response, the pituitary gland increases the secretion of ACTH in an attempt to stimulate the adrenal cortex. However, because the adrenal glands are not functioning properly, ACTH levels rise significantly. ACTH has a structure similar to melanocyte-stimulating hormone (MSH), which can lead to increased production of melanin by melanocytes in the skin, resulting in hyperpigmentation.

This hyperpigmentation is often more pronounced in areas exposed to friction, such as the elbows, knees, and other body creases, as well as on mucosal surfaces. This finding, in conjunction with symptoms like fatigue, weight loss, and hypotension, helps clinicians to diagnose Addison's disease.

In contrast, the other conditions mentioned do not typically present with hyperpigmentation as a primary feature: Cushing's syndrome is characterized by excess cortisol