Itches, Twitches, Tickles, and PopsThe itchy and the scratchy
If you have an itch, what could you do but scratch it?
If you're Dr. Gil Yosipovitch, nicknamed the "Godfather of Itch," you could study it, too. Yosipovitch has investigated all things itch, including the relationship of itch and acne, eczema, and dry skin; how an itch can be felt on the body and in the mind; and how the brain reacts to scratching.
It may seem strange to devote so much effort to a small thing like an itch. You just scratch it and it goes away, right? Not so for some people. Itch can be a chronic, unbearable burden for people with certain skin conditions or other underlying conditions.
Many itches originate on the skin, some spring from disorders of the nervous system, and still others are creations of our minds. We most often get the urge to itch because of things that happen on the surface of our skin, like allergic reactions from touching certain materials (e.g., poison ivy), dryness, or insect bites. Sometimes a rash accompanies a skin itch, but not always. Other itches stem from internal causes. Kidney failure, liver disease such as hepatitis, thyroid conditions, and some neurological disorders may cause an itchy sensation.
The common link between all the different sorts of itches? The undeniable reflex to scratch. You scratch, Yosipovitch found, because it actually helps to shut off a part of your brain associated with the emotional reaction to an itch, including the annoyance and memory of it. Over 20 years ago, itch researchers disproved the common belief that itch was actually just another form of pain. In fact, itch has its own nerve pathways and in some cases its own nerves. Like pain, an itch causes a reflex reaction. But whereas pain triggers the reflex to pull away draw back from it, an itch draws you right to where it lives - and then you scratch! But starting to scratch can set off a vicious cycle of itch-scratch-itch-scratch that can not only irritate but damage the skin.
Next up on Yosipovitch's research agenda: why does watching someone scratching an itch - or just reading about the subject - make you feel the urge to scratch?