What is the difference between coated and hairy tongue?
The difference between these two terms is basically that of the degree of keratin accumulation. With coated tongue, the accumulation is not severe. With hairy tongue, the amount of keratin is such that hair-like projections of the keratin material form on the top of the tongue. What about the color of my tongue? Sometimes it seems black or brown. Because the keratin is composed of dead cells, this material can act as a place for the normal bacteria found in the mouth to accumulate and grow.
