Acanthosis nigricans is a skin disorder characterized by dark areas of skin, with velvety color changes in the folds and wrinkles. At the same time, the affected skin also can become thicker. In most cases, it affects the armpits, groin, and neck.
Skin changes from acanthosis nigricans often occur in people who are obese or who have diabetes. In addition, children with this disease are at greater risk of developing type 2 diabetes.
On rare occasions, acanthosis nigricans can be a warning sign of a cancerous tumor in an internal organ, such as the stomach or liver.
There are no specific treatments for this disease. However, the treatment of undiagnosed disorders can restore some normal color and texture to affected areas of skin.
Symptoms of acanthosis nigricans
Skin changes are the only signs of the disease. Darker, thicker, and more velvety skin is seen in the folds and wrinkles of the body. These symptoms usually occur in the armpits, groin, and also the back of the neck.
Most of the time, skin changes appear slowly. At the same time, the affected skin may also have an odor or stinging sensation.
Check with your doctor if you notice any skin changes, particularly if they appear suddenly. You may have an undiagnosed condition that needs treatment.
Causes
Acanthosis nigricans has been associated with the following:
- Insulin resistance – Many people who have acanthosis nigricans have also become resistant to insulin. Insulin is a hormone secreted by the pancreas that allows the body to process sugar, and insulin resistance is what ultimately causes type 2 diabetes.
- Hormonal disorders – Acanthosis nigricans often occurs in people who have hormonal disorders. For example, ovarian cysts, an underactive thyroid, or problems with the adrenal glands.
- Certain medications and supplements – High doses of niacin, birth control pills, prednisone, and other corticosteroids can cause acanthosis.
- Cancer – Acanthosis nigricans can also occur with lymphoma or when a cancerous tumor begins to grow in an internal organ, such as the stomach, colon, or liver.
Risk factors
The risk factors for acanthosis nigricans are as follows:
- Obesity: The greater your weight, the higher the risk of contracting this disease
- Race: Studies show that in the United States, acanthosis nigricans is more common
- Family history: Some types of acanthosis nigricans seem to run in families
The diagnosis of this skin condition
Dermatologists usually use a skin test in order to detect acanthosis nigricans. On rare occasions, a specialist will remove a small sample of skin for biopsy and send it to a laboratory for analysis.
If the cause is unclear, your doctor may recommend that you have blood tests, X-rays, or other studies. The purpose of these studies is to look for possible undiagnosed causes.
Treatment for acanthosis nigricans
In many cases, treating the underlying disease can help dissipate the color changes. Some examples may include the following:
- Losing weight. If the cause of acanthosis nigricans is obesity, then losing weight can be helpful.
- Discontinue medications or supplements. If the condition appears to have to do with the medication or supplement you’re taking, your doctor may suggest that you stop taking it.
- Undergo surgery. If the cause behind the condition is a cancerous tumor, then surgical removal of the tumor usually makes the change in skin color go away.
How to improve the appearance of the skin
If you’re concerned about the appearance of your skin or your lesions become uncomfortable or begin to smell bad, your doctor may recommend the following:
- Prescription creams to lighten or soften affected areas
- The gentle use of antibacterial soaps, as friction can make the condition worse
- Topical antibiotics
- Oral acne medications
- Laser therapy to thin the skin
Tests and Examinations
Your doctor can usually diagnose acanthosis by looking at your skin. In rare cases, a skin biopsy may be necessary. If there’s no clear cause, the specialist may order other tests. These may include:
- Blood tests to check blood sugar or insulin levels
- Endoscopy as a diagnostic method
- X-rays
