Acanthosis nigricans
Overview
Acanthosis nigricans is the name for dry, dark patches of skin that usually appear in the armpits, neck or groin. It could be a sign of an underlying condition, so it needs to be checked by a GP.
Symptoms
The main symptom of acanthosis nigricans is patches of skin that are darker and thicker than usual. They can appear anywhere on the body. The patches often appear gradually without any other symptoms. Sometimes the skin may be itchy.
Causes
The most common cause of acanthosis nigricans isobesity. Other causes include: type 2 diabetesconditions that affect hormone levels – such asCushing's syndrome,polycystic ovary syndromeor anunderactive thyroidtaking certain medicines – including steroids or hormone treatments like the contraceptive pillrarely, cancer – usuallystomach cancerrarely, a faulty gene inherited from your parents Sometimes healthy people with no other conditions get acanthosis nigricans. This is more common in people with black or brown skin.