Acanthosis nigricans is the term used for thickened, darkened skin on the neck or in body folds, such as under the arms.
You are more likely to have AN if:
In most cases AN is a sign that you are gaining too much weight. It is also often a sign that you are starting to have type 2 diabetes. If you have AN, it’s very important to get checked for type 2 diabetes and other possible causes. The skin changes often get better with the improved diet and exercise that treats or helps prevent diabetes. Much less commonly it can be associated with other illnesses, including cancer.
You have a painless area of darkened, slightly raised skin. The skin may feel velvety. In rare cases it may itch. As it develops over weeks, it may make the skin look dirty.
Your healthcare provider will examine your skin and ask about your symptoms and family medical history. You may have lab tests to look for signs of diabetes or other health problems that might cause AN. If there is any question about what it is, you may have a skin biopsy. When you have a biopsy, you are given a numbing medicine and then your provider removes a small piece of skin. The skin sample is sent to a lab, where it is examined under a microscope.
There is no specific treatment. If AN is caused by an illness, like diabetes, treating the illness AN to go away with treatment of the illness. When AN seems to be a side effect from a medicine, your provider may prescribe a different medicine. If you have the inherited form of AN (called familial acanthosis nigricans), a cream or lotion for the skin, prescribed by your healthcare provider, may be helpful.
Talk to your healthcare provider and work with him or her to find and treat the underlying cause.
The best way to try to prevent AN that’s not the inherited type is to have a healthy weight and diet, along with regular physical activity. Together these good health habits can help prevent blood sugar problems that can lead to diabetes and AN.
