Adrenal insufficiency causing a generalized bronze hyperpigmentation, most prominent in sun-exposed areas, palmar creases, and on mucous membranes.
Certain forms can cause hyperpigmentation due to excess ACTH, similar to Addison's disease, in the context of ambiguous genitalia or precocious puberty.
While typically causing other skin signs (striae, easy bruising), ACTH-dependent Cushing's can also cause diffuse hyperpigmentation from excess melanocyte-stimulating hormone activity.
Certain drugs (like minocycline or amiodarone) can cause a distinctive slate-gray or blue-black discoloration, particularly in sun-exposed areas.
An iron overload disorder that leads to a characteristic "bronze" or metallic gray skin hyperpigmentation, along with liver disease and diabetes.
