Acanthosis nigricans (dark velvety skin)

Overview

It isn't dirt and won't scrub off.

Sudden widespread patches in an adult can rarely signal cancer.

It's common in people with obesity, type 2 diabetes, and PCOS.

Some medicines like high-dose niacin and steroids can cause it.

Symptoms

Common signs:

• Dark velvety skin in folds
• Dark spots or patches on the skin
• Dark, velvety skin in body folds

Less common

• Skin tags nearby
• Itching

When to get medical care

Causes

Insulin resistance.

Does it spread or run in families?

• It isn't contagious. You can't catch it from someone else.

Who is more likely to get it

• Obesity

Possible complications

• Prediabetes

Diagnosis

A clinician checks blood sugar.

Tests

Tests, if needed:

• A1C:

Treatment

Treat the cause.

Self-care

• Lose weight
• Exercise
• Lose weight slowly
• Exercise most days
• Use gentle moisturizers
• Don't scrub the skin

Prevention

To lower your risk or prevent problems:

• Healthy weight
• Regular activity

Which doctor treats this

• Start with your primary care provider (family doctor or internist).
• They may send you to a dermatologist (skin doctor).

Children, pregnancy, and older adults

• Children: A sign to check for prediabetes.

Pregnancy and breastfeeding

• If you're pregnant or planning to be, tell your prenatal provider about this condition.
• Some skin medicines, like isotretinoin and retinoid creams, aren't safe in pregnancy.
• Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
• Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
• Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Improves.

Often fades as blood sugar improves.

Getting ready for your visit

Bring a list of your symptoms and medicines.

Questions to ask

• Do I have prediabetes?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Acanthosis nigricans (dark velvety skin)