What is a common symptom of Addison's disease related to skin appearance?

In Addison's disease, a common symptom related to skin appearance is the darkening of both exposed and unexposed skin. This hyperpigmentation occurs due to increased levels of adrenocorticotropic hormone (ACTH), which stimulate melanocytes, the cells responsible for skin pigmentation. The excess ACTH results from the body's attempt to stimulate the adrenal glands, which are underactive in Addison's disease. Consequently, patients often notice a bronzing of the skin, particularly in areas such as the scars, pressure points, and skin folds, contributing to a distinctive appearance.

This symptom is an important clinical indicator of Addison's disease and plays a role in the diagnosis, along with other symptoms such as fatigue, weight loss, and low blood pressure. Understanding the connection between ACTH and skin pigmentation helps in recognizing the disease and differentiating it from other conditions that might cause skin changes.