The neck is dark and always feels like there is a layer of ash on the surface, but how to wash it just can’t get it off, even repeatedly rubbing and stimulating it won’t work. In the clinic is more common, there are some parents with children to see the doctor, there are also some adults themselves appear this condition. It will be found that these people are fat, due to obesity, in the neck, underarms, groin and other folds, some pigmented lesions, touching like velvet protrusion, called benign acanthosis nigricans, its occurrence is related to obesity. After this situation, the main thing is to lose weight, to reduce the weight, this neck black situation, will also be slowly improved.