I recently stopped at a motel along Route 66, where I encountered a pearly-white creature crawling on the pillow that would send an itch through my entire body. Of course, I assumed the worst: That it was a bed bug and that my skin, even though I had yet to even lay down on the bed, was crawling with them.
From that moment on it became a sort of motel ritual of mine: I’d arrive at a new motel room, sweep the sheets off the bed, examine the mattress and, even when I didn’t find anything, I would itch my back until it was red. Needless to say, there were no bed bugs — or at least, I had no actual bed bug bites on my body. Yet every so often I would catch my brain playing games with me, leading me to believe that my body was infested with microscopic, toothy, blood-sucking bugs.
Of course, I’m far from alone in this pseudo-Pavlovian itch experience. “Why do I feel so itchy after seeing small bugs, even though no physical contact was made?,” one redditor asked five years ago. Another person on Quora also wondered why they itch even just when they think about bugs.
Before we get to explaining that, though, it’s important to understand what causes us to itch in the first place. While symptoms of itching vary, according to Medicine Net, any “peculiarly uncomfortable skin sensation,” caused by a rash or toxins on or under the skin, can lead to the need to itch. “Medically, itching is known as pruritus,” per the same report. “Something that is itchy is said to be pruritic.”
To that end, there is plenty of research that explains why people feel like their skin is itching, even when there’s nothing physically present on their skin. In 2012, researchers at the University of Manchester found that visual cues, including but not limited to seeing images of insects, can provoke an itch response in people, even if they haven’t felt a thing. “In fact, you may not even need to see the itch-inducing stimulus, as the same study found that just seeing another person scratch can make viewers feel that they also have an itch to scratch, suggesting that itching, like yawning, may be a socially contagious response,” reports The Mary Sue.
Additionally, using images of ants crawling or a butterfly on the fingertip, the researchers discovered that “visual cues alone (without application of any irritant to the skin) do indeed elicit sensations of itch in an observer and provoke a scratch response,” reports The University of Manchester. For that reason, the researchers actually recommended that to help better treat people with chronic skin itching, medical practitioners should combine elements of psychology with dermatology.
Past experiences can also play a part. “University of Pennsylvania neuroscientist Dr. Wenqin Luo places the blame for phantom itch on memories of an itchy past,” reports NBC News, so seeing something that may have made you itch in the past will trigger the scratching response now. As for why that doesn’t also translate to phantom pains when we think about past trauma, Dr. Luo told NBC News that, “Compared with itch, pain is a serious protective mechanism that triggers avoidance behavior. Thus, the threshold to trigger a pain sensation may be much higher than that of itch.”
Luckily for me, the feeling that I was itching all over largely disappeared after I finished my road trip. For many, however that’s not the case — there’s an actual medical condition where people constantly feel like their skin is itching all over. “Formication is the feeling of insects crawling across or underneath your skin,” reports Healthline. “The name comes from the Latin word ‘formica,’ which means ant.” Per the same report, the causes of Formication include fibromyalgia and Parkinson’s disease. “Withdrawal from alcohol or drug use can also trigger formication,” reports Healthline.
All of which is to say that I am, as of writing this, itch-free. But chances are, the next time I see any sort of bug crawling around my apartment, the memory of those scuzzy motel rooms is going to send my body into an itch-fit.