Stimulants What exactly can meth do to your tongue?

[artfart]

My very close friend, whom we'll call Ezra, has come to me with a problem after falling off the wagon for the first time in a long time. After smoking,he felt something like a burning sensation on his tongue,similar to the feeling after taking a drink of something that's a little too hot. He has his tongue pierced and he tells me that he sees raised red bumps on the outer edge of his tongue ring, under the ball. He sent me two pictures, one being right after smoking and the other several hours later.

Although the cracks went away, it still seems to be discolored and irritated in the second photo. He's told me that he has never experienced this before. What could the stuff have been cut with in order for it to have this effect? Besides brushing and keeping up with oral hygiene - is there anything else that Ezra can do to sooth the (very mild) discomfort he is feeling?

Thanks in advance for the help.
-A