Cure For The Itch

Why do we itch? Is there a cure?

Counterirritation is an effective treatment, used for decades, based a simple idea:

Pain masks the itch

For example, if you’re suffering from poison ivy, taking a very hot shower can bring some relief, or ingesting something with capsaicin, the pain-inducing compound in hot peppers such as jalepenos, can be effective. Can the nerves that transmit sensations of pain and itch be separated or are they intrinsically intertwined? As shown in this “ball of nerves,” separation of sensations is no easy task.

i-ad3a2b5ea0c5c4dbfb72e95239198370-08927-scitech1-fluorescentcxd-thumb-250x238-67010.jpg
Courtesy of Xinzhong Dong

Ball Of Nerves

Just before sensory nerves meet up with the spinal cord, they get bundled into a small knot, called a dorsal root ganglion. In this image, receptors on various sensory nerves coming into that bundle (cross section about 0.5-mm diameter) are tagged with fluorescent markers.

According to the Chemical & Engineering News article (July 4):

What has emerged is a more complex, population-dependent view of pain and itch. Scientists now believe that some population of sensory neurons contains only pain receptors and responds only to pain. Then there are itch-regulating neurons that have receptors for both pain and itch. If a stimulus activates both neuron populations, pain occurs. But if an itchy stimulus triggers only the neurons that respond to both itch and pain, Carstens says, “what the brain interprets from that mix is an itch.”

Of course, anti-inflammatory treatments such as Methylprednisolone can help but often bring unexpected side effects. My dermatologist prescribed me this medication to treat poison ivy, informing me that it may cause insomnia or euphoria. Oddly, my side effect was euphoria. Too bad it had to end when the irritation from the poison ivy subsided.

So finding a treatment that can separate pain and itch remains a significant challenge. In the meantime, you can always rely on the counterirritation approach – but do so in moderation!

Or you can listen to Linkin Park’s “Cure For The Itch.” If not a cure, at least the dancing will distract you from the itch.

For my Linkin Park concert review, click here.

Comments

  1. #1 Miss MSE (@MissMSE)
    July 8, 2011

    I discovered years ago that slapping mosquito bites was far more effective relief than scratching them, and they healed much faster without the additional damage from my nails. I get some strange looks, but it works well for me. Itching is a fascinating phenomenon. There’s a group of “itch scientists” who argue there’s a significant psychological aspect to itching (http://jscms.jrn.columbia.edu/cns/2008-04-01/witherington-itchydeath.html is a nice post on the concept).

  2. #2 tripencrypt
    July 8, 2011

    After a bout of poison ivy on my forearms, I found that using a hand held blow dryer to blow hot air on the site of the inflammation significantly reduced itching. It wasn’t perfect, I would almost give myself a burn and the effects lasted for about 5-10 minutes. That little break, especially when 60% of my forearms were inflamed made a big difference to me.