Scratch

As I've mentioned, I injured myself a while back, but I'm healing. One of the ways I know this is that I can feel a deep itch, not unpleasant but there, in my ankle. It's not a mosquito-bite itch, but just sort of a dull, insistent bristling, way under the skin and inside the joint. It's what it feels like to heal from a sprain, at least for me.

It could be worse. Have you read this New Yorker piece by Dr. Atul Gawande about uncontrollable itching, including the almost un-think-about-able story of a woman who had such a persistent scalp itch that she actually scratched through her skull into her brain?

Anyway, let's try to put that out of our heads. The medical term for "itch" is "pruritis", from the Latin "prurire", "to itch" (logically enough). Doesn't that remind you of another English word? Such as "prurient"? Sure it does. But "prurient" means "having or causing lustful or impure thoughts". What gives?

Nothing too strange. "To have an itch" idiomatically means "to have a desire for": the itch to travel, for instance. When you have a literal itch, you can't be comfortable, you twitch, you can think of nothing else. Same thing when you have that figurative itch. And when you can't help your lubricious thoughts, well, that's a kind of itch, too.