Why do we itch? Is there a cure?
Counterirritation is an effective treatment, used for decades, based a simple idea:
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.
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.