Written by Dr. Sanjana V.B Bhms,dbrm,cdn
Founder & medical director of siahmsr wellness.in

Reviewed by SIAHMSR

 Overview

  Acanthosis nigricans is a skin pigmentation disorder manifested as dark patch of skin with a thick, velvety texture. Dark, thick and velvety patches are usually found on skin folds and on areas like armpits, back of your neck, groin, elbows, face, knees, knuckles, and soles of the feet and underneath female breasts.

 Acanthosis nigricans appear as velvety hyper-pigmented patches with poorly defined borders on these areas.It is often a sign of underlying diseases.  Acanthosis nigricans is strongly associated with pre-diabetes, insulin resistance, diabetes, polycystic ovarian syndrome, metabolic syndrome and obesity.  Sometimes, acanthosis nigricans can be a warning sign of serious disease conditions such as cancers in a few percentages of people.

  Although this skin disorder is not completely curable, it is manageable if the underlying cause is removed or treated. Some lifestyle changes and dietary modifications also have crucial role in managing acanthosis nigricans arising from less serious causes such as insulin resistance, diabetes, obesity etc.

Wisely chosen diet plans, exercise programs and some medications can reverse the disorder in cases stemming from insulin resistance. It is very important to maintain a healthy lifestyle to manage it for a longtime.

What are the causations of acanthosis nigricans?

·  Insulin resistance or prediabetes

 Insulin resistance is a state in which the insulin hormone produced by pancreas cannot help to remove glucose from blood and use it for energy by the cells. Various factors like genes, lifestyle, obesity, some other hormonal disorders like polycystic ovarian syndrome etc. may cause insulin resistance. Eventually it may progress to prediabetes and diabetes  if left untreated .

·  Diabetes mellitus

   Acanthosis nigricans is often found in diabetic people on neck and skin folds.

·  Certain medications

   Glucocorticoids, oral contraceptives and some medications such as corticosteroids  can trigger acanthosis  nigricans.

·  Genetic or hereditary

   Acanthosis  nigricans is sometimes seen in childhood,  and it is linked with genetic inheritance . This type of acanthosis nigricans is called familial acanthosis nigricans.

· Obesity

  Acanthosis nigricans is commonly associated with obesity and overweight. This usually associated with lifestyle and mostly seen in adults.

· Hormonal disorders

 Certain disorders of ovary such as polycystic ovarian syndrome ,an insulin resistance state and uncontrolled diabetes may gradually lead to appearance of acanthosis nigricans on the skin folds.

· Autoimmune diseases

 Some autoimmune diseases like SLE, Sjogren's syndrome, scleroderma  are  associated with acanthosis nigricans.

· Malignancies or cancers.

 Acanthosis nigricans commonly occurs in individuals younger than the age of 40 years, mainly in Native Americans, African Americans, and Hispanics. It is mostly seen in people in connection with obesity, under active thyroid, acromegaly, polycystic ovary disease, insulin-resistant diabetes, Cushing, and Addison diseases etc.

However in a few groups of people acanthosis nigricans is found in association with cancers. It is found in individuals having stomach, lung , breast and pancreatic cancers.  It is most commonly associated with stomach cancer or gastric adenocarcinoma.

                                                                                                                           SIAHMSR

How does acanthosis nigricans develop on the skin?

 The development of acanthosis nigricans occurs most probably due to growth factor levels and insulin-mediated activation of insulin-like growth factor (IGF) on keratinocytes of skin.

It is related to the proliferation of fibroblasts and the enhanced stimulation of epidermal keratinocytes of skin. This is the major cause of development of acanthosis nigricans in persons having obesity, high insulin levels and diabetes  with metabolic syndrome[1].

In patients with malignancy or cancer and acanthosis nigricans, the most probable stimulating factor is secreted by the cancer cells.

Signs & symptoms

 Acanthosis nigricans appear as area of darkening and thickening of the skin with itching, and may be associated with skin tags.

Obesity is one of the most common conditions associated with Acanthosis nigricans. Skin tags also are often found in and around affected areas.

This skin lesions  appear  in adults as velvety, dark patch that progress to palpable plaques. Acanthosis nigricans mostly occur in areas of skin folds like the groin, axilla and on the back portion of neck.

 In children, acanthosis nigricans is seen mainly on the back of neck. Rarely, acanthosis nigricans may occur on the mucous membranes of the nose, oral cavity, esophagus, or larynx. Women also may develop acanthosis nigricans on the nipple.

Complications of acanthosis nigricans

 Complications of acanthosis largely depend on the cause. Most cases of acanthosis arise from insulin resistance, diabetes, PCOS and other less serious causes. The prognosis is better in these cases after treating the underlying conditions. Cosmetic treatments also help to a large extent. 

 However serious complications like cancers may be associated with acanthosis nigricans and have variable outcome depending on the type and stage of cancers. Prognosis in patients with the malignant form of acanthosis nigricans is poor mostly, as the malignancy might have advanced at the time of diagnosis.

 What is Malignant or cancerous acanthosis nigricans?

 Acanthosis nigricans may appear on skin before any signs of cancer occurs. It is considered as a warning sign of cancer although it is seen in less serious conditions also.

Malignant Acanthosis nigricans is associated with gastrointestinal cancers and cancers of prostate, breast, and ovary. Lung cancer and lymphoma are also associated with acanthosis nigricans rarely. Malignant acanthosis nigricans may precede, accompany, or follow the onset of internal cancer and is manifested suddenly with itching [4].

How to diagnose acanthosis nigricans?

Investigations

 Acanthosis nigricans is diagnosed by clinical examination of the patient and confirmed with a skin biopsy. On biopsy, hyperkeratosis, leukocyte infiltration, epidermal folding, and melanocyte proliferation may be seen. Biopsy of acanthosis nigricans is not routinely done, but it is ordered in suspected cases of malignancy or cancers.

 As acanthosis nigricans can be associated with pre diabetes, diabetes, metabolic syndrome and polycystic ovarian syndrome etc. Certain investigations like fasting blood sugar, hormonal assays & ultrasonography of pelvis are done.

Blood tests, endoscopy, or x-rays may be required to eliminate the prospects of diabetes or cancer.

 Measuring glycosylated hemoglobin is also recommended to rule out diabetes and insulin resistance.

How to manage acanthosis nigricans?

There is no complete cure for acanthosis nigricans. Addressing the underlying conditions which are leading to acanthosis  is the main line of treatment. Some risk factors and diseases causing insulin resistance are managed with medications, exercise and healthy diet.

If obesity is the major cause, weight reduction may help to reduce the dark patches of acanthosis nigricans [5].

Insulin resistance associated with diabetes, poly cystic ovarian syndrome and metabolic syndrome  is managed with medications, exercise programs, stress reduction techniques ,life style and dietary modifications. Controlling blood glucose levels through exercise and diet often improves symptoms.

 Topical application of creams can lighten skin in less severe cases.

Acanthosis nigricans associated with insulin resistance may be treated with drugs such as metformin and rosiglitazone which are insulin-sensitizing agents by conventional medicine doctors [6].

Acanthosis nigricans associated with malignancy may resolve if the causative tumor is removed successfully.

 According to one research study melatonin could improve cutaneous symptoms in obese patients with acanthosis nigricans by improving insulin sensitivity and inflammatory status [7].

If acanthosis nigricans appear as a side effect of medications or supplements discontinue them or replace them as per the directions from a physician.

 Cosmetic treatments:

If there is so much concern about dark patches of acanthosis nigricans, cosmetic treatments are available to remove them.

Cosmetic treatments include:

Skin lighteners like Retin-A, 20 percent urea, alpha hydroxyl acids, and salicylic acid 

Oral medications

Dermabrasion

Laser therapy

 These treatments can fade the appearance of acanthosis nigricans but cannot  cure the condition completely. The removal of the exact cause of the condition is the most effective solution for acanthosis nigricans.

Alternative and complementary medicines

Homeopathy

 Medicines are focused on managing the underlying causes in an individualized manner. Homeopathy uses oral medications to address the causes with individually chosen  constitutional medicines.

Important homeopathic medications used for managing acanthosis nigricans are:

Argentum nitricum, arsenicum album,carbo animalis, conium maculatum,lycopodium,sepia,  &Sulphur. 

 Other medications to remove the underlying causes include:

Diabetes with acanthosis:

Argentum nitricum,insulinum,lycopodium,phosphorus, syzygium jambolanum, cephalandra indica.

 Polycystic ovarian syndrome:

graphites,kalium carbonicum,sepia.

Obesity:

calcarea, graphites, lycopodium,phytolacca berry.

 In homeopathic medical science ,medicines are chosen in an individualized manner taking into account the symptoms as well as the underlying causes of the clinical condition.

FAQ -Frequently asked questions

1..How does acanthosis nigricans look like on skin?

2. What are the diet &life style modifications for  managing acanthosis nigricans?

 To reduce insulin resistance and control associated diseases like diabetes ,PCOS and metabolic syndrome , low glycaemic index foods are recommended in the diet

The low glycaemic foods may not produce a quick spike in the blood sugar levels in diabetic patients.

Fibers also are promoted as part of the diet to reduce blood sugar and bad cholesterols. It also helps in reducing obesity associated with insulin resistance.

For extra reading on obesity management or weight loss in acanthosis 

1. Mediterranean diet for weight loss

https://siahmsrwellness.in/mediterranean-diet-for-obesity  

2. Obesity & weight loss solutions

https://siahmsrwellness.in/obesity-weight-loss-solutions 

3. What are the diseases commonly found in association with acanthosis nigricans?

 Acanthosis nigricans is strongly associated with pre-diabetes, insulin resistance, diabetes, polycystic ovarian syndrome, metabolic syndrome and obesity.  Sometimes, acanthosis nigricans can be a warning sign of serious disease conditions such as cancers in a few percentages of people.

4. Is acanthosis nigricans a sign of cancer?

 Acanthosis nigricans may appear on skin before any signs of cancer occurs. It is considered as a warning sign of cancer although it is seen in less serious conditions also. Malignant Acanthosis nigricans is associated with gastrointestinal cancers and cancers of prostate, breast, lung and ovary. However, every acanthosis lesion is not cancer, it may be found in association with diabetes and various other diseases.

copyright of the article @Dr Sanjana vb siahmsr

References           

1.       https://pubmed.ncbi.nlm.nih.gov/29184811/

2.       https://pubmed.ncbi.nlm.nih.gov/29209995/

3.       https://pubmed.ncbi.nlm.nih.gov/27921251/

4.       https://www.ncbi.nlm.nih.gov/books/NBK431057/

5.       https://pubmed.ncbi.nlm.nih.gov/15186199/

6.       https://pubmed.ncbi.nlm.nih.gov/18492785/

https://pubmed.ncbi.nlm.nih.gov/29706998/