By itself Acanthosis Nigricans is not harmful or contagious. Many people who have it have no other symptoms and are otherwise healthy. Often, Acanthosis Nigricans can be a sign of diabetes or other medical conditions. In such cases superficially treating the pigmentation may not yield the desired results, finding and treating the health problem is necessary. Therefore in cases with diabetes or obesity, getting sugar levels and weight under control can help to clear up the pigmentation.