Acanthosis nigricans can affect otherwise healthy people, or it can be associated with certain medical conditions. Sometimes acanthosis nigricans is congenital (something a person is born with). It also can occur as a result of obesity or an endocrine (glandular) disorder. It is frequently found in people with diabetes or a tendency towards diabetes and is most common among people of African descent. There are many other possible causes of acanthosis nigricans, including:
Most people with acanthosis nigricans have an insulin level that is higher than that of people of the same weight who don't have acanthosis nigricans. Eating too much of the wrong foods, especially starches and sugars, can raise insulin levels.
Rarely, people with certain types of cancer can also develop acanthosis nigricans.