Tapeworm, I hear stress brings on canker sores/cold sores. They are the absolutely worst!
Perhaops GB is causing you too much stress

Bit of sunburn & chapping along with a couple of physically hard days at work.
put dry ice on it, boom it will be gone!
And only a scar to remember it by?
Apply sparingly. 
Are
sure you're a certified sawbones?