A very, very old fashioned treatment for thrush (oral yeast infection) in children is " Gentian violet" -- the purple liquid that folks used to use on cuts, too. People used this before there were antibiotics for everything. When I was a kid back in the 1960s, there were always some kids in the school yard with big, purple Gentian Violet splotches on their knees.

Nearly 40 years ago, my daughter had thrush. The young pediatrician prescribed 2 or 3 rounds of a liquid medicine (maybe the nystatin that a previous poster mentioned) but it didn't work. The older pediatrician-- who seemed a little irritated with the younger doc-- told us to use the gentian violet, and it worked after one, single application! It worked on my sisters' babies, too.

If you want to use it, know that:
1. Do NOT swallow it;
2. It permanently stains everything it gets on. A Q-tip is a good applicator. It might make your gums and teeth look a little purple for a day or two;
3. You should check with your doctor before you use it!
4. If you have to ask a doctor or pharmacist for it, "gentian" is pronounced like jen - sen, with stress on the jen. I haven't seen it on the pharmacy shelf in a long time but I haven't needed to look for it, either.

Good luck--hope you can get rid of it soon!

(I really hope that we don't forget the effective treatments from before the era of antibiotics...I think we may need them again in the future as the bugs get resistant.)