Has he got any spots on feet and hands ? How long has this been going on ? Have you taken him to the doctor ?
@Katie no no spots it’s been 3 months one goes another one comes, they said it comes with viral infection but he’s fine
@Heather I have tried we even changed his toothbrush
Keep trying different toothpastes, mine are triggered by toothpaste, it was my dentist who told me to keep trying different brands as I had 3/4 at a time all time
Allergic to anything? Putting things in mouth that may be dirty?
Try changing his toothpaste to one without sodium laurel sulphate (sls) as that can trigger mouth ulcers if sensitive to it