Acanthosis nigricans are areas of dark, thickened, and velvety skin that can appear on the neck, thighs, or vulva. The disease itself is not dangerous or contagious, although you may not like the way it looks. However, since this could be a sign of other medical conditions, you should discuss it with your healthcare provider.
Symptoms of black acanthosis
Dark, thick and velvety skin develops slowly in areas of the body that have skin folds, usually in the armpits, groin, and neck crease. Some people refer to the neckline as a sugar line or a sugar necklace (due to its association with diabetes ).
Pigmentation can also appear in the joints of the fingers and toes. The skin remains soft, unlike other syndromes, when the skin hardens. Less commonly, pigmentation appears on the lips, palms, or soles of the feet, and is more often associated with cancer .
Acanthosis nigricans can be seen in healthy people, so it is not always associated with any disease. However, this is due to such conditions:
- Obesity: most frequent association; weight loss can reverse it
- Genetic disorders: including Down syndrome .
- Cancer of the digestive tract, liver, kidney, bladder or lymphoma: rare.
- Polycystic Ovarian Syndrome (PCOS) and Ovarian Cysts
- Medications: birth control pills, human growth hormone, high doses of niacin, prednisone, and some other medications .
- Type 2 diabetes: A 2016 study noted that more than half of children with type 2 diabetes had acanthosis nigricans. It also often develops in adults with diabetes .
Insulin resistance and acanthosis nigricans
Insulin resistance means that the body does not respond to insulin as well as it could (this happens, for example, in people with PCOS and people with prediabetes). Insulin forces glucose into the body's cells to be used for energy.
A person with insulin resistance will need to secrete more and more insulin before glucose reaches the body tissues and ultimately changes the way the body interacts with sugar. One of these methods is the introduction of additional pigment .
Report your acanthosis nigricans symptoms to your doctor, who will examine your skin and can usually diagnose it by its appearance. Your doctor will likely also order blood tests to measure your blood sugar or insulin levels. An endoscopy or X-ray may also be done to look for cancer and other causes.
The main treatment for acanthosis nigricans is to address the underlying cause. Weight loss and changes in insulin resistance are the most effective ways to reverse any changes in the skin. This is reversible and will go away as the cause is removed.
Topical retinoids increase the flow of normal skin cells, which can reduce the appearance of damage. Both dermabrasion and laser therapy are procedures that should only be performed by a board-certified dermatologist.