tomatoes causing gums to peel

Hi,

I just noticed this a couple of months ago, I was eating a salad and suddenly noticed some of the gum in the back teeth started to peel... not much, just a little but noticeable to my tongue. Two days later it was almost healed completely.

I didn't really know at that point that it was done by the tomatoes.
I eat salads almost two times a week, but i don't get this effect every time I have one.

Then the other day I ate a slice of pizza at my uncles house, and the peeing started again!!!

So I'm guessing since the only thing in common in my salads and pizza was the tomato... that this is the cause.


You guys know why this happens, and why only certain tomatoes do it?
And if it could worse as time passes by?

Thanks, I appreciate your information

Sergio