The itch roundtable

When I heard back in December about the NIAMS (division of the NIH) itch roundtable--a discussion that involved the NEA's CEO Julie Block, a number of NIAMS directors, and a larger number of active itch researchers--I was excited that the meeting summary would be made public. I don't know why it is, but in the media you hear about eczema much more from the allergy perspective, or as if it's a cosmetic issue with dry skin, rather than the reality for a lot of us: chronic itch. If we could control the itch, we'd be less at risk of infection, we wouldn't prolong our flares, and possibly most importantly, we'd have more self-respect.

It's hard to feel like you're a grown-up when your self-control in this one dimension is no better than a three-year-old's.

The summary of the itch roundtable was recently put online (at the link above). I got there by following a link in the email the NEA sent all its members. At the end of the summary there's a long list of the participants. I plan to check out what research they're all doing.

Two things jumped out at me from the summary. The first thing is that itch research is building on the much more established field of pain research. It appears well-known that certain types of pain can inhibit itch. (And, in fact, that the same type of neuron carries both impulses.) As an eczema patient I know this very well first-hand. In fact, sometimes scratching feels good precisely because it hurts, and seems to spread a cool blanket of pain over the burning itch.

I've got a rather silly story to relate about this. When I was a teenager I discovered this pain-itch connection, and I happened to have an itchy scalp at the time. I found that a good way to relieve the itch was to pull out small clumps of hair. Ouch! you say. Ouch is right. Felt great. I did this for about a week.

The problem was that I then developed an extremely nasty case of something like eczema herpeticum--little fluid-filled blisters that spread all over my body and threatened to leave me looking sandblasted for life. Fortunately my parents took me to a doctor who prescribed some magical cream that completely reversed the infection. I have no idea what the cream was, only that it worked, and that my parents said it was "very strong." It must have been an antibiotic of some kind.

Dr. Sib, if she still reads this blog--will remember this episode. During the recovery period, I drove her crazy by picking at my scabs.

So don't try that at home.

The second thing that jumped out at me from the summary was that, although mice are the standard laboratory model animal for many human diseases, there are several key reasons why itch in mice and humans is substantially different at the molecular level and at the level of the skin as an organ. Therefore, it's unlikely that a mouse model will be developed for human itch. To quote NIAMS:

• Itch- and pain-specific neurons and receptors identified in mouse models may not have the same distinct functions in humans.
• Structural differences in mouse and human epidermis may create differences in itch transduction, and downstream cellular activity (e.g., protease production).
• Overexpression of many cytokines in mice will induce non-specific itch, whereas the itch mechanisms in humans appear to be more complex.
• Current mouse models correspond to acute itch, whereas clinical itch tends to be chronic.
• Linking itch mechanisms from animal models to the spectrum of itch descriptions in human patient populations can be challenging, because some behaviors in animal models, such as scratching, licking, and biting that are attributed to the condition may be unrelated to it.

These complications with animal models will slow itch research. But pain research has faced similar hurdles, and is more advanced as a field, so we can hope the scientists can piggyback their work on existing pain research.

Will we see "itch centers" in the U.S.?

One thing that often gets neglected in articles about eczema is itch. To those of us who suffer from eczema, the itch is virtually the core of the problem. No itch? Then we wouldn't scratch. And we wouldn't have the gashes and tears. Who would care about dry skin or a bit of redness if we could get into bed at night knowing that we wouldn't stay awake, or in a half dream-state, frantically scraping our hands or heads or the backs of our knees or whatever.

Just typing that last sentence, I had two involuntary fits--now three--where my hands leapt of their own accord--now four, five--to my scalp or face and indulged themselves in a frantic scrabble that must seem twitchy and obsessive to a "normal" person.

Chronic itch, it seems, can sensitize our central nervous systems so that very minor stimulation triggers an urge to scratch. Or we just get itchy for no reason at all. The sensors in our skin fire by themselves. But you read articles about eczema that talk about moisturizing and managing your diet as if our rashes appeared by themselves. These articles must be written by people who don't have eczema themselves.

I read today in Skin and Allergy News that the U.S. may in the near future see certain premier medical institutions found centers for itch treatment. Apparently Europe already boasts several such centers, and I interpret the article to say that the centers have a centralized database of tens of thousands of patients. The collected data is being used in studies to determine what triggers itch and how doctors might alleviate it.

One treatment for chronic itch, the story says, is "second-generation antihistamines." Intriguing. I didn't know there was such a thing. All I know is that what must be first-generation antihistamines--Claritin and Allegra--do nothing for me.

The article also mentions "neuroleptic" (read: antipsychotic) meds and drugs that affect the central nervous system. Now, I'm not anti-Western medicine by any means, but the hairs on my neck stood up a little when I read that part closely. If it's a choice between being the slightly weird guy who's always scratching something and being the impotent, lethargic insomniac, I'll go for Itchy 'n Scratchy.

Of course, there are other conditions besides eczema that cause itch: liver or kidney disease, or shingles. And when you start scratching a hole in your head, it's time to medicate.

The new centers in the U.S. may launch at the University of California, San Francisco; Washington University in St. Louis; and Harvard. Since I live in the SF Bay Area, this is pretty exciting for me (and not so exciting for you, if you don't). But there's another issue: this is the U.S., with its messed-up medical "system," and my current insurance doesn't cover treatment at UCSF, which is ridiculous, since I WORK at the University of California. Say UCSF launched an itch center, and I really needed an appointment; it might be that my doctor could refer me to UCSF. Or I might have to pay out of pocket. It would be a lot simpler if the U.S., or even California, had something approaching a single-payer healthcare system.

These centers are, at the moment, pie-in-the-sky. But they could happen. Timothy Berger, MD, at UCSF, claims in the Skin & Allergy News piece that "The NIH is moving to a model of having major itch referral centers at several sites." Berger was quoted commenting on a recent "roundtable" session hosted by the National Institute of Arthritis and Musculoskeletal and Skin Disease (NIAMS), part of NIH: the roundtable was focused on exclusively on itch, and was the first such discussion held by NIAMS. It came about because of lobbying by the National Eczema Association, according to Julie Block, the NEA's CEO, who told me so last week in our conversation. "We're so excited we got NIAMS looking," she said. "There's nothing ever been done so specific to itch." Block, or another NEA representative, was invited to take part in the roundtable.

Did I mention that you should donate to the NEA?

According to Trish Reynolds, the media rep at NIAMS, they'll post a meeting summary by the end of December. I'll be interested to read it and to get comment from the scientists involved about what they think is feasible.