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Dirty Marks

Published: Thu May 01, 2014
Categories: The Myth Minx

Dirty looking marks on the skin is a condition called Acanthosis Nigricans, AN for short. Fortunately this is uncommon; however, the pseudo form of acanthosis nigricans, isn’t. 

 Acanthosis Nigraicans or AN and the faux AN look essentially identical.


Since ‘Acanthosis’ means thickening or overgrowth of the upper layers of the skin, and ‘Nicgricans’ means dark or black – put it together and we really do get a description where you expect to see - a dark thickening or overgrowth of skin. AN is a brown to black, poorly de­fined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the folds in the back of the neck and lateral folds of the neck, under the armpits, groin, thighs and naval, as these are the areas of the body where the skin tends to rub together.

 Since the back of the neck is so easy to see, AN is normally first discovered by someone’s family member, who often mistakes it for dirt on the skin. Despite the obvious cosmetic and emotional issues that can be associat­ed with AN, the medical importance of AN, is whether it reflects some­thing of importance, internally. In most cases, the pseudo form can be a result of being overweight. The real AN stems from more of an internal issue.

AN can be caused by higher than normal levels of the hormone insulin, due to an insulin resistance in the body. The hormone insulin is responsible for getting your blood sugar into your cells for energy. If your insulin isn’t working well, our pancreas will produce more and more insulin to try and get blood sugars into the cells. The skin cells react by changing the level of colour or pigment in the skin but this only occurs in skin that has already been stretched or rubbed.

AN can also stem from medications (such as the contraceptive pill or corticosteroids) or certain endo­ crine diseases such as polycystic ovaries, diabetes (the next step to having high insulin levels), hypo­thyroidism, and other less common hormonal imbalances. AN can also be a sign of an internal cancer related back to gastro, intestinal tract, the ovaries or even the lung, prostate or breast.

There are still some cases of AN who have no apparent association to disease, and they are not overweight.

AN is diagnosed by detecting the characteristic skin changes during skin examinations. Sometimes a skin biopsy is obtained for lab examination. If the cause of AN is unclear, other investigations may be required such as blood test, X-ray and other test to identify the underlying cause.


For the first group who have AN as a result of being overweight or certain endocrine diseases –

treating the underlying condition will result in a remarkable improvement in the Acanthosis.

A change in diet can be beneficial in reversing insulin resistance, and inflammation. Regular exercise and a low GI, high fibre, wholefood diet will support health, well - being and reduce blood glucose levels thereby dramatically reducing the risk of associated diseases such as Metabolic Syndrome and Type 2 diabetes.

In most cases AN is not harmful and it is definitely not contagious – but medical attention is required, to ensure there is no other underlying disease that may require medical treatment.

So there we have it take note of those dirty marks on the skin and look after yourself, your skin may be trying to tell you something.

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