Eh, Noctalys, you reminded me of something nasty.
(This one was SO painful once I actually REALIZED what had happened.)
I'd had my ears pierced a while ago, and had just gotten to the point where I could swap earrings. Without knowing that I was allergic to the el cheapo ones from the local chemist. So, of course, I had a major allergic reaction. Sitting in class, scratch scratch scratch, oooooh, it's gone all warm and slippery, that's nice, scratch scratch... Suddenly the whole room goes DEAD quiet (quite the achievement for 32 rowdy teenagers!) and look at me in disbelief. "What?" They point at my hand. Covered in blood. O-kay... I look at my book. HOLY CRAP!!!! I look at the collar of my pretty blue shirt. EVEN HOLIER CRAP!!!!
Let's just say that my shirt took three trips through the washing machine, my book was a write-off, I almost fainted from blood loss and I never wore an earring in that ear again. Allergies suck.
I know, I know, this is probably dead, but once something gets set in my mind, it must be told...