Acanthosis nigricans is a skin condition that causes it to become thicker and darker, issues known as hyperkeratosis and hyperpigmentation in scientific terms. It usually affects the groin, armpit, back of the neck or other areas where the skin folds. It is not actually a disease, but the skin effect of another disease that is not directly visible.
Doctors divide acanthosis nigricans into benign and malignant varieties. The most common types are the benign ones, also named pseudoacanthosis nigricans. The malignant types are very rare and are considered to be a manifestation of internal malignant diseases.
Acanthosis nigricans is not harmful at all and can't be transmitted. Because of this, some people notice the darker color and assume they came in contact with a dye or another pigment. They usually try to scrub away the paint, which is futile, since it can't remove the condition.
Even if the acanthosis nigricans is not a serious condition, it can signal a much more serious issue that requires immediate treatment. Don't ignore its symptoms and consult a dermatologist if your skin becomes darker and thicker in some places.
Acanthosis nigricans is caused by the skin epidermal cells reproducing a lot faster than normal, which creates thick patches. The most common cause is a very high level of blood insulin but other possible causes exist. These include diseases such as cancer and also several types of medication.
In most cases, extremely high levels of insulin in the blood are the cause of acanthosis nigricans. Insulin is a hormone that plays a key role in the human metabolism. The carbohydrates from the food we eat are converted after digestion into glucose and other sugar molecules. Glucose is used to produce energy or stored as a reserve for the future. Insulin makes it possible for glucose to pass through the cell walls, where it is used as energy.
Insulin is produced in the pancreas but some people are unable to use it properly. People who gain too much weight become resistant to the effects of insulin, which causes serious problems. Since glucose is unable to enter the cells, it remains in the blood stream, where large amounts of glucose and insulin start to build up.
One of the effects of the high insulin levels is the accelerated reproduction of healthy skin cells. People with darker skin tones will produce new cells with an increased content of melanin pigment, which causes whole zones of skin to look darker than the rest. This behaviour makes acanthosis nigricans a very worrying sign, since it predicts the onset of diabetes. However, the blood insulin level can be controlled using drugs, a healthy diet and daily exercises.
Some medications and treatments can also cause acanthosis nigricans. These are usually hormone related, for example human growth hormones, thyroid medications, bodybuilding supplements and the ubiquitous birth control pills. These hormones don't have a direct impact but actually boost the levels of blood insulin. The condition can also be triggered by some of the drugs used to counter the effects of cancer chemotherapy. In this case, the condition is temporary and will disappear after the treatment is stopped.
Acanthosis nigricans also has other possible causes, but these situations are quite rare. It can be the result of diseases such as a dysfunctional pituitary gland, Addison's disease or various other problems of the adrenal gland, gastric adenocarcinoma and other types of stomach cancer. It can also be the side effect of high doses of niacin, as well as insufficient amounts of thyroid hormones.
Acanthosis nigricans has a slow progress, the symptoms are only visible at skin level and it doesn't cause any other problems. The vulnerable areas are parts of skin that fold on the neck, armpits or groin, as well as the joints of toes and fingers. The skin becomes dark, with a velvet aspect, covered by obvious marks.
Some people, especially if they also suffer from cancer, can have additional areas of the skin affected as well. These can include the palms, soles of the feet or the lips.
Since acanthosis nigricans is not a disease itself, but the effect of other conditions, it can't be treated directly but the root disease has to be healed. In most cases, the symptoms disappear if the underlying disease is cured.
The treatment depends on the cause of the condition. For example, if acanthosis nigricans is triggered by some drugs, stopping the medication can be enough to cure it. High insulin levels can be reduced using medication, as well as diet or exercises. If the disease is due to obesity, losing weight will eliminate it. Cancer can also be the underlying disease, which can be removed surgically or treated in several ways. There is also a hereditary variant of acanthosis nigricans. There is no treatment for it but the lesions usually regress and disappear on their own, after an initial period of expansion.
The condition itself can't be treated directly. However, there are numerous treatment options for the symptoms. These are often used only for cosmetic reasons, effective treatments are laser therapy, topical retinoids or dermabrasion.
Since acanthosis nigricans is the sign of another disease, its progression is directly linked to it. In many cases the root has a benign nature and will eventually heal itself in time, due to healthier lifestyle choices. Malignant acanthosis nigricans is a lot more serious, since it signals very dangerous diseases. It can be the effect of an advanced form of cancer, which is usually fatal in 2 years or less.