Hyperpigmentation--dark spots or areas on the skin--results from the overproduction of skin pigment, called melanin, or the deposit of color from another process in the body. Causes of hyperpigmentation can be harmless or life-threatening, according to the journal "American Family Physician." Hyperpigmentation requires evaluation by a physician to determine its cause and rule out serious disease.
Hemochromatosis
Hemochromatosis is an inherited condition that causes the body to absorb too much iron from foods. The excess iron causes damage to the organs that store it, most commonly the heart, liver and pancreas. Signs and symptoms may not appear until age 30 to 50, and can include chronic tiredness, arthritis, abdominal pain, high blood sugar and abnormal levels of liver enzymes. In later stages, signs of organ damage appear. Liver cancer or cirrhosis, congestive heart failure, diabetes and abnormal heart rhythms can result. The skin may develop a widespread bronze or slate-gray hyperpigmentation from iron deposits, explains American Family Physician.
Melanoma
Melanoma is the deadliest form of skin cancer, according to the American Academy of Dermatology. It can spread rapidly to internal organs. Exposure to sunlight or indoor tanning equipment may cause some cases of melanoma. It often develops on or near an existing mole on the skin, but can develop suddenly on normal skin. Changes to an existing mole that may warn of melanoma include an irregular border, variations of color from one part of a mole to another, the presence of tan, brown, black, blue, red or white color and increasing size. On normal skin, the sudden development of a new mole or area of hyperpigmentation may warn of melanoma.
Acanthosis Nigricans
Acanthosis nigricans are hyperpigmented areas that appear brown and velvety or leathery, according to American Family Physician. The hyperpigmentation of acanthosis nigricans commonly develops in patients who are obese or resistant to insulin. Common locations for the lesions include the neck, armpits, groin and at the belt line. This condition commonly signifies a risk of developing diabetes, polycystic ovary disease or high levels of fats in the blood. Rapid development, especially on the palms and soles, may signify cancer somewhere in the body.
References
- American Academy of Family Physicians: Common Hyperpigmentation Disorders in Adults--Part I
- The Merck Manual for Healthcare Professionals: Hyperpigmentation
- American Academy of Family Physicians: Common Hyperpigmentation Disorders in Adults--Part II
- MayoClinic.com: Hemochromatosis
- American Academy of Dermatology: Malignant Melanoma
