The soft tissues of the mouth can be damaged easily by chewing tobacco held in the same spot for long periods of time. Chew will irritate the tissues for two reasons; it contains elements which are toxic, and believe it or not, the tobacco companies actually put small amounts of aluminum oxide (used for sand blasting) and other micro abrasives into the mix to irritate the tissue and allow the nicotine quicker access to you. Unfortunately, this also allows more rapid access to the toxic elements as well. It is likely that what you are experiencing will go away in a few days without the use of any chew, combined with some good oral hygiene. If after two weeks it hasn't cleared up, and you've been diligent about not using and keeping your mouth really clean, then it is time to visit your dentist and let him have a look. Take a minute and read some of our tobacco pages on this site, and check out a site called NSTEP which is a group of sports figures against chew. (Oral cancer has taken the lives of a few of their colleagues who used spit tobacco). After all this, make an intelligent choice about whether you want this stuff in your life any more. Perhaps what you get out of it, isn't worth the risk