My latest bad-boy canker sore!
This is my current canker sore, I swear that writing about them has made this one come. All in the mind!
Click it for a full size picture
I am treating him with Adcortyl in Orabase, a tube I purchased way back before it got discontinued in the UK.
Will let you know how it goes. I think I have had too much hot drinks today which is irritating it, causing the red outline you can see.

Corlan tablets are really good, you keep it on the ulcer with your tongue. It is a steroid, but can be bought over the counter in the U.K.
Thanks Jan, I have heard of these, and some people buy standard orabase (dental paste without any active ingredient) and mix in the Corlan tablet. It is a corticosteroid just like triamcinolone acetonide so probably does the same kind of job.