What Causes Hyperpigmentation?

The Condition

Hyperpigmentation is caused by an increased deposit of melanin in the skin. While everyone knows people tan and darken with sun exposure, over-darkening of the skin can also can be caused by a disease process. This includes more common endocrine problems and other conditions and treatments.

Hormones

Hormonal changes cause hyperpigmentation, because the manufacture of melanin is greatly influenced by the endocrine system. The hormone pumped out by the pituitary gland that produces melanin is melanocyte-stimulating hormone, or MSH. Conditions such as Addison's Disease, Nelson's Syndrome and hemochromatosis can lead to an overall darkening of the skin. Other diseases--such as polycystic ovarian syndrome and severe insulin resistance--result in acanthosis nigricans, which is basically darkened patches of skin. Pregnancy brings its own hormonal changes, such as the so-called "mask of pregnancy"--or darker patches of skin on the face.

Lesser-known Causes

Other lesser-known causes of hyperpigmentation include the rarer deposit of silver in argyria. This condition is associated with people using colloidal silver as an alternative medical treatment, in which the skin turns to a bluish-dark gray color. Another example is melanogenesis--basically, tanning or darkening of the skin--as seen in hemochromatosis, or bronze diabetes, in which the body stores an excess of iron. This affects the endocrine system and production of melanin.

Resources

• Conditions That Cause Hyperpigmentation