Discussion Forum—A Way with Words, a fun radio show and podcast about language

I was familiar with the phrase "a wild hair up one's ass" when my wife, an RN, was using "wild hair" to describe body hair that was inappropriate.   I have a few really-long hairs in my eyebrows, which she loved to pluck out over my protests; those, she said were wild hairs.   She had a long hair, only one, growing out of her ear lobe - not the center of her ear, like us old geezers develop, but the dangle-down part.   I don't know if this as a back-formation, or what, but she made fun of me before friends and cow-orkers, and they all seemed to be aware of the term.

How old is the phrase "a burr up his ass", indicating that someone is highly touchy, ready to fly off the handle at the slightest provocation?   Is one derivative of the other, or is it more likely that hemorrhoids and suppositories   have made us all highly sensitive to "incoming freight on he shipping dock" (as National Lampoon phrased it in "The Job Of Sex")?