You might mistake it for a tan or brown stain and try to scrub it off. But it won’t work. This condition is common in people with diabetes. Your skin usually darkens and thickens, and it might feel velvety. It could itch and smell, too. The back of the neck, groin, folds of elbows, knees, knuckles, and armpits are common spots. Being overweight or obese ups your chances for acanthosis nigricans, so shedding pounds can help get rid of it.
These might pop up suddenly on your fingers, toes, hands, feet, and sometimes on legs or forearms. They’re usually white with no red around them. The blisters might look scary, but they usually don’t hurt and heal on their own in about 3 weeks. They could be a sign that you have diabetes or that your blood sugar levels aren’t controlled. Talk to your doctor about your symptoms.