Have you noticed darker, thicker skin around your neck, under your arms, or in other skin folds?
You may have assumed it was simply pigmentation, friction, or something that could be scrubbed away.
But if the skin is darker, thicker, and has a velvety texture, it may be a condition called acanthosis nigricans.
While acanthosis nigricans itself is not harmful, it can sometimes be an external sign of what is happening internally. It may be associated with insulin resistance, prediabetes, diabetes, PCOS, certain medications, and other medical conditions.
What Does Acanthosis Nigricans Look Like?
Acanthosis nigricans typically appears as areas of skin that are:
Darker than the surrounding skin
Thicker or more textured
Velvety to the touch
Located in skin folds or creases
Common locations include:
The back of the neck
Under the arms
The groin
Knuckles
Elbows
Knees
The neck and underarms are particularly common locations.
What Causes It?
Acanthosis nigricans can have several causes.
One of the most common is insulin resistance.
When the body becomes less responsive to insulin, the pancreas may produce more insulin to help keep blood glucose within range. Elevated insulin levels may contribute to changes in the skin that result in the characteristic thickened, darker appearance.
Acanthosis nigricans can also occur in association with:
Prediabetes or diabetes
PCOS
Certain hormonal conditions
Certain medications
Family history or genetic factors
Not everyone with acanthosis nigricans has insulin resistance, so the skin finding should be evaluated in the context of the individual.
Is It a Sign of Diabetes?
It can be.
Acanthosis nigricans may be an early sign of prediabetes or insulin resistance, even before someone develops obvious symptoms of high blood sugar.
This is one reason it is worth paying attention to changes in your skin rather than simply trying to lighten or scrub away the discoloration.
Depending on your history, your healthcare provider may consider evaluating blood glucose and metabolic health.
What About PCOS?
Acanthosis nigricans can also occur in women with polycystic ovary syndrome (PCOS).
PCOS is not simply a reproductive condition. It can involve hormonal and metabolic changes, including insulin resistance in some women.
If you have acanthosis nigricans along with irregular periods, acne, unwanted facial or body hair, difficulty with weight management, or other hormonal symptoms, a broader evaluation may be appropriate.
Can Acanthosis Nigricans Go Away?
Sometimes.
When an underlying condition is identified and appropriately managed, the skin changes may improve. For example, addressing metabolic health and improving insulin resistance may help the appearance of the skin over time.
However, improvement is not always immediate, and treating the underlying issue does not necessarily make the skin changes disappear completely.
It is also important to avoid aggressively scrubbing the area. This generally will not remove acanthosis nigricans and may irritate the skin.
When Should You Have It Evaluated?
If you notice new dark, thickened, or velvety skin, especially around the neck or underarms, consider discussing it with your healthcare provider.
An evaluation may be particularly helpful if you also have:
A family history of diabetes
Irregular menstrual cycles
PCOS
Difficulty managing weight
Increased hunger or cravings
Fatigue
Other metabolic or hormonal concerns
If the changes appear suddenly or spread rapidly, prompt medical evaluation is especially important because, although uncommon, rapidly developing acanthosis nigricans can be associated with underlying medical conditions that require investigation.
The Bigger Picture
Sometimes the body gives us clues before a laboratory result does.
A change in your skin may be more than a cosmetic concern. It may be an opportunity to take a closer look at your metabolic and hormonal health.
At Prestige Functional Medicine, we look beyond individual symptoms to understand the bigger picture. Depending on your history and symptoms, that may include evaluating metabolic health, hormones, nutrition, and other factors that may be contributing.
If you’ve noticed changes in your skin and are wondering what they could mean, a personalized evaluation can help determine whether further testing is appropriate.
