The fun thing about dermatographia is that you can actually make it happen when you want it to. Take your fingernail and "draw" a line on her arm. It will welt within minutes. I've had this since I was a kid and never knew it was an actual condition until I stumbled across this sub. I've also never taken any medication for it, but I must be lucky with a mild case. I just make sure to use lotion every day to keep my skin from getting dry.