What Is Acanthosis Nigricans?
Acanthosis nigricans (pronounced: ah-kan-THO-sis NY-gruh-kans) is a skin disorder that results in velvety, light-brown-to-black patches or marks that occur in areas of your skin that has folds, including the neck, armpits, groin, and under the breasts.
These markings may appear as though they can be scrubbed away, but you can't remove them. Also, they're not contagious, so you don't have to worry about spreading it to others or catching it from someone.
Acanthosis Nigricans Symptoms
One main sign of acanthosis nigricans is the thick, velvety, light-brown-to-black patch that often appears in the skin folds in the front or back of your neck, armpit, elbows, knees, belly button, or under your breast.
Acanthosis nigricans might also feel itchy and smell, but it doesn't cause pain.
Rarely, you might have it in your nose, mouth, throat, vocal cords, or eyelids. It might also show up on the nipples, areolae, and vulva and between your anus and vulva. If your acanthosis nigricans is related to cancer (which is rarely the case), you might have symptoms on your palms, soles of your feet, and lips.
This skin condition shows up slowly, taking months to a year. If you suddenly see them on you, see a doctor or dermatologist immediately, as it could be a sign of cancer.
Acanthosis Nigricans Pictures
Acanthosis Nigricans Causes
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 obesity with diabetes or prediabetes and is most common among people of African descent.
There are many other possible causes of acanthosis nigricans, including:
- Addison's disease, a condition caused by a deficiency of hormones from the adrenal gland
- Disorders of the pituitary gland within the brain
- Growth hormone therapy
- Hypothyroidism (low levels of thyroid hormone caused by lowered activity of the thyroid gland)
- Oral contraceptives
- Polycystic ovary syndrome, a hormonal imbalance problem in people assigned female at birth
- Corticosteroid medications
- Autoimmune conditions like lupus and Sjogren's syndrome
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.
In rare cases, people with certain types of cancer can also develop acanthosis nigricans.
Acanthosis Nigricans Diagnosis
A dermatologist can diagnose the condition by looking at your skin. Your doctor may also take your medical history and perform a physical exam and blood tests to determine if another health condition, like prediabetes or thyroid disease, is causing your acanthosis nigricans.
In rare cases, your doctor may also test a sample of your skin tissue if the other tests don't point to any obvious cause. This test is called a skin biopsy. They could also do it to confirm your symptoms are not from cancer.
Acanthosis Nigricans Treatment
Eating a special diet can help reduce circulating insulin and may lead to some improvement of the acanthosis nigricans.
Treatments to improve skin appearance and lighten the skin area include Retin-A, 20% urea, alpha hydroxy acids, lactic acid, topical vitamin D, and prescription-strength salicylic acid. These don't work very well, though.
Your dermatologist may also recommend:
- Laser treatment to reduce the skin's thickness
- Antibiotics and antibacterial soaps to reduce the odor and itchiness
Your skin may also improve once you get treatment for other conditions that cause acanthosis nigricans. For example, surgery to remove a cancerous tumor may also result in the patches fading.
But your patches may not go away even after treating the conditions that cause them. Remember, some people have it even without having a related health problem.
Acanthosis nigricans caused by a drug may go away once the medication is stopped.
Can Acanthosis Nigricans Be Prevented?
When acanthosis nigricans is related to obesity, weight management is an important part of prevention. A diet that contributes to reduced insulin also can help prevent acanthosis nigricans.
Other ways to prevent the condition include treating related medical problems like hypothyroidism and avoiding medications that tend to cause or worsen the condition (like birth control pills).
Takeaways
Acanthosis nigricans is a skin disorder that may happen in otherwise healthy people but often shows up in people with obesity, prediabetes, or diabetes. It may also be a sign of other hormonal and autoimmune conditions, and rarely cancer. See a dermatologist if you notice light-brown-to-black patches on your skin, especially if they appear suddenly. Treating any underlying conditions may improve your skin's look. Your dermatologist may also recommend skin care products and laser therapy to improve your symptoms.
Acanthosis Nigricans FAQs
Can acanthosis nigricans go away on its own?
No, acanthosis nigricans will not go away on its own. However, your dermatologist may recommend skin care treatments to improve your skin's look.
What is the best treatment for acanthosis nigricans?
The best treatment for acanthosis nigricans is treating any underlying conditions causing it, like obesity or diabetes. If you have acanthosis nigricans for no obvious reason, creams, ointments, and other skin care products your dermatologist prescribes could be the best way to improve your symptoms.
What skin condition is similar to acanthosis nigricans?
Terra firma-forme dermatosis, or Duncan's dirty dermatosis, looks like acanthosis nigricans. It is a rare skin disorder that causes velvety, dark brown-blackish patches that look like dirt spots.
Can you have acanthosis nigricans on your face?
Yes, you can have acanthosis nigricans on your face, including your nose, mouth, and eyelids, but this is rare.
