A reader Stephanie writes:
I had a terrible experience with chronic itch, which is (I believe) rarer and less respected than chronic pain. But I can tell you, it was horrifying, and from what I hear about effects of and treatments for chronic pain, chronic itch is quite similar. It would be nice if chronic pain professionals would include chronic itch in their purview.
Thanks, Stephanie, for an interesting question. I don’t know all that much about chronic itch, but here are some thoughts. I’d be interested in readers’ knowledge as well, or more from Stephanie about her experiences, to share in the comments.
Like in chronic pain, you have to determine if chronic itch is a symptom of a problem, or the problem itself. Let’s look at this more closely: Chronic pain can be a symptom of an underlying disease, e.g. cancer or multiple sclerosis. Or chronic pain can result from a disease process in the pain systems themselves, e.g. CRPS. Similarly, chronic itch can be a symptom of a minor problem, e.g. dry skin, or a more serious disease, e.g. kidney problems. Or, itch can be a disease of the “itch” system itself.
We used to think that itch sensations travel along the same nerve pathways as pains do. However, scientists more recently discovered a separate set of nerves, with wide reach throughout the skin, that seem to be dedicated only to itch.
Another connection between itch and pain is that the body’s opioid system seems to be involved. There are opioid medications (also called narcotics), e.g. morphine, as well as opioids that occur naturally in your body. We’ve known for a long time that a side effect of narcotic medication can be itch. So this led scientists to study how medication that blocks this opioid system might help pain. And guess what… in some cases, it does help significantly.