(uh-kan-THO-sis NIH-grih-kans):

a skin condition characterized by darkened skin patches; common in people whose body is not responding correctly to the insulin that they make in their pancreas (insulin resistance). Patches may appear on the neck, under the breast, in the groin area, in an armpit or top of the knuckles. This skin condition is also seen in people who have pre-diabetes or type 2 diabetes.