canthosis nigricans
(EH-can-THO-sis NI-greh-cans)
is a skin disorder characterized by abnormally
increased coloration (hyperpigmentation) and "velvety"
thickening (hyperkeratosis) of the skin, particularly of skin fold
regions.
It is often described as dark patches of skin, frequently
on the back of the neck. Sometimes people get a dark ring around their neck. Other possible sites for these dark patches include elbows, knees, knuckles, and armpits.
Acanthosis is associated with
insulin resistance and pre-diabetes,
and with
polycystic ovary syndrome.
Acanthosis nigricans will improve or resolve with treatment of the underlying disorder.
Since acanthosis nigricans may occur in up to 90% of children with
type 2 diabetes,
it is an important clue in the detection and diagnosis of this increasingly-common
form of diabetes in children: See
diabetes in children and adolescents: fact sheet
