I have a solution - brush your teeth with Rembrandt Anti-Canker Sore Toothpaste. You can get it at pretty much any grocery store/drugstore and it's specifically formulated to stop canker sores from forming. Apparently, there's some ingredient in most toothpastes that cause canker sores for a lot of people, and this toothpaste doesn't include it.
I used to get canker sores all the time, one after the other, until I started using this toothpaste. Since then, I rarely get them (maybe one or two every few months).
A related discussion,
mystery illness was started.
My elderly doctor prescribed Kenalog with Orabase for my canker sores about 10 years ago. This is the greatest medication for cankers that I have ever had! My doctor has since passed away and very few new doctors have even heard of Kenalog with Orabase, however it seems that most pharmasists are familiar with it. If you can get your hands on this prescription, it's wonderful. It's a paste that you apply to your canker sores at night. It reduces swelling and pain dramatically and shortens the life of the sore. It's truly a wonderful thing! Good luck!
You might try taking Lysine for awhile. It is a supplement available at the drug store over the counter. It should be pretty cheap, and is easy to take. It worked for me & others. I have also heard tea tree oil is good dabbed on & spit out, not swallowed. Have never tried this, but know some who find it very effective. Good luck!
I'm afraid I can't offer much. We presume that canker sores are viral, but no one's ever proved this. They aren't herpes, by the way.
Cankers, like so many other things, make no sense. Your internist is no doubt correct that you're basically healthy. I doubt that you'll have them indefinitely, at least at this level of intensity. More likely, they'll bother you for a while, then revert to once-in-a-while. Meantime, apply a soothing anesthetic--like Orajel, or scotch--and wait 'em out. Check with your doctor from time to time, too.
Best.
Dr. Rockoff