ROBERT SIEGEL, host:
Here's a corollary to that impossible suggestion, try not to think of an elephant. During the next conversation, as you hear us talking about itching and scratching, try to itch and don't scratch. Dr. Atul Gawande is both a surgeon and a staff writer for the New Yorker, and he has an article that explores itching the current issue of the magazine, and he joins from Boston. Welcome to the program.
Dr. ATUL GAWANDE (Surgeon; Staff Writer, The New Yorker Magazine): Thank you for having me.
SIEGEL: And let's start with what seems like it ought to be an easy question, but I gather is anything but: What is an itch?
Dr. GAWANDE: It is hard to define. No one's improved on the definition from 1660: An unpleasant sensation that provokes the desire to scratch.
SIEGEL: And there's been some work in trying to identify what is it that exactly is itching when we feel an itch under the skin, say.
Dr. GAWANDE: Yeah. For the longest time people - scientists had theorized that itching was just a grade of pain - a very mild form of pain - and that it must be transmitted along pain receptors. But then it was only in the late '80s that they did experiments where they gave poor subjects very itchy things and could turn up the amount of itch substance driven into their skin. And they found that they could reach a maximum tolerable level of itch, and yet not have pain. And that led them to separate the idea that there is itching, and it's totally different from pain.
SIEGEL: And while many of us might think in terms of fairly modest itches as you're talking about this, there's some medical horror stories you relate in this article about people who have uncontrollable itches that lead them to - I mean, they can scratch through flesh and bone, given an itch.
Dr. GAWANDE: Yeah. That's a terrible case that got me thinking about what is thing, itch, was a case reported in the medical literature of a woman who was so tormented by an itch that would not go away that she would scratch during her sleep. And the scratching during her sleep one night led her to scratch through her own skull and into her brain.
SIEGEL: It is a horrible story, but I gather that her case is not unique in the sense that if people have a persistent itch that cannot be undone by ointments or by medications of some sort, it's likely it's not - a doctor may tell them this could just be in head, this itch.
Dr. GAWANDE: Yeah. What happens is that there is itching that you can trace to something in the skin - a psoriasis, or a cream you shouldn't have been using. But then there are itches that seem to come from something else altogether. You can have itches that come from jaundice, itches that come from a tumor, even in your own brain. And there are people who are so tormented by constant itching -and I introduce, unfortunately, a parade of these folks - who can scratch incessantly and feel that they're itchy for years on end to the point that they can't work, they can't function, they can't concentrate.
SIEGEL: I warned people at the outset not to itch during this interview. And one of the things, as you write in the article, that's, I think, unique to itching is we could be talking about wildfires in California and people wouldn't start to feel burning sensations. We could talk about all kinds of pain and we wouldn't feel pain, but itch is something that you can start feeling based on the power of suggestion.
Dr. GAWANDE: Yes. If I just describe to people the feeling of an ant crawling along the back of their neck and up their scalp, you can't help it. You start to feel itchy, and you wonder if that thing is there. And that power that itching has to be provided simply by suggestion suggests that there's something more interesting to our perceptions than just that you trigger a nerve, it goes up your spinal cord to your brain, and then it rings a bell in the brain, like a clapper ringing a bell. Here are cases where you don't have the clapper, and yet the bell continues to ring.
SIEGEL: As we talk about this, or as you wrote the article, for that fact, did you find yourself itching a lot?
Dr. GAWANDE: I did. Especially when I was describing how lice, for example, cause you to itch on your scalp, or describing how a group of flies could make you itchy just by brushing very lightly across your skin. Just writing about those led me to have to stop for a moment and check myself to see whether there really was a bug where I thought there might be.
SIEGEL: Well, before we cause too many rush hour traffic accidents from people scratching as they're listening to us, I want to say goodbye and thank you.
Dr. GAWANDE: Thank you.
SIEGEL: That's Dr. Atul Gawande, who is a staff writer for the New Yorker magazine. His article in the current issue is called "The Itch."