Acanthosis nigricans is a skin disorder where the skin becomes brown to black, thick and velvety particularly at the body folds and creases like the forehead, armpits, groin and neck. This discoloration and thickening of the skin is most commonly associated with obesity. Acanthosis nigricans is more common in darker skinned people and only occurs in less than 1% of the Caucasian population. However, it affects about 20% of overweight children thereby indicating the strong association with obesity. Although rare, it is also linked to stomach cancer irrespective of the race of the cancer patient.
Skin whitening is a term used for lightening the complexion of the skin through artificial means like creams, lotions, soaps and injections. Certain skin diseases like vitiligo causes a ‘skin lightening’ effect due to the lack of the natural skin pigment at the affected area. However with skin whitening applications, the skin is ‘forced’ to prevent its natural skin pigment production and distribution due to the action of pharmacologically active and potentially toxic chemicals.