Just a guess, but I would be willing to bet quite a few dollars that the red irritated areas, that are slightly itchy, contain teeth. Especially if there is a slight bump in the middle of the red area. Is it slightly painful if you push on the red area? Very similar to removing a splinter, I would squeeze gently around those areas, and don't be surprised by how big the teeth are. Ball pythons (don't quote me on this) have around 240 tooth sockets in there mouth, and shed teeth fairly frequently. If I remember correctly, they average about 180 teeth on any given day (due to some being lost).
Hope that helps,