I have been itchy all damn day after reading this post by our Daily Intelligencer pals on the return of bedbugs, and I suspect I’m not the only one. As one commenter put it:
welp thanks for this now i've got psychosomatic itchy spots all over because i take the N Train all the time ... i fought the scourge back in '12 and still feel em on me. STILL FEEL EM CRAWLING ON ME.
I hear you. But I was curious how simply reading about something creepy and crawly could be enough to induce a physical sensation, so I reached out to Robert Provine, a neuroscientist at the University of Maryland, Baltimore County, and author of Curious Behavior: Yawning, Laughing, Hiccupping, and Beyond.
Here’s what he said:
Itching and scratching, like yawning, laughing, coughing, and vomiting, is contagious. Simply seeing someone scratching is enough to trigger your own bout of clawing, in a vain effort to rid yourself of pests, real or imagined. You don't need to actually be bitten by a bedbug, louse, or flea — simply seeing their image, thinking about them, or reading about them — as you are doing now — may trigger a seesaw bout of itching (the stimulus), and scratching (the response).
This hair-trigger, contagiousness and hyper sensitivity to itchy stimuli makes make sense. Your neighbor's pest may jump ship and infect you. Better start scratching, just in case. Unfortunately, scratching causes more itching, locking you into an escalating cycle of itch and scratch.
Apparently, I'm trapped in a vicious cycle of itch and scratch, because evolution. Awesome.