THE ACANTHOSIS NIGRICANS. SYMPTOMS AND CAUSES.

The acanthosis nigricans is a dermatosis which is characterized by the hyperpigmentation and the cutaneous hyperkeratosis. It is considered like a cutaneous sign of resistance to the insulin in different illnesses or syndromes of the endocrine system like, for example, the type 2 diabetes or the obesity. It is showed with signs of thickening of the skin and papillomatous prominences with some dryness, of velvety appearance and cutaneous roughness. The pigmentation varies between a brown, black and grayish tonality and it gives a dirty appearance to the skin. It is generally located in armpits, neck, groins and other cutaneous folds. The acanthosis nigricans is more frequent in Afro-descendant, Latin and Caucasian population. It is not only a dermatological illness but it is also a demonstration of several systemic disorders. The acanthosis nigricans is classified in two types made up by the acanthosis nigricans of mild appearance and the other is of malignant appearance associated to a paraneoplastic syndrome. The acanthosis nigricans is divided in several types:

• Hereditary or familiar. As its name indicates it is of genetic etiology.
• Syndromatic benign. It is related to endocrine, genetic or immune cases.
• Genetic origin with Sub-Saharan ancestry.
• It has a genetic origin, it appears during childhood and it stabilizes during adult ages.
• Pseudo-acanthosis. Associated to the metabolic syndrome by an obesity reason.
• Pharmaco-induced. Due to the interaction of medicines responsible for the hyperinsulinemia. Corticoids, contraceptive pills and hormonal treatments can be a frequent reason.

The malignant acanthosis nigricans is linked to malignant tumors, like for instance, the adenocarcinomas of abdominal organs. There are no specific treatments to fight the acanthosis nigricans. In some cases may disappear without any reason although taking exercise and a healthy diet is very important to help to solve the case. In those cases in which the acanthosis nigricans is due to an underlying cause, the treatment of the latter will help the improvement or the disappearance of the acanthosis nigricans.