I am pretty certain that by the time you finish this article, you will be seeing the dual actions of itching and scratching in a different light.
The Science of Scratching
When something bothers the skin, like a mosquito bite, cells release a chemical, usually histamine. That release provokes the nociceptors in the skin to send a message to the spine, which then relays the message through a network of nerves called the spinothalamic tract up to the brain.
In 2009, researchers used a histamine injection to make the legs of non-human primates itch while an electrode monitored what happened inside their spinothalamic tracts. As soon as the histamine was injected, those neurons began to fire, and fast too; but when the researchers offered up a few scratches, those neurons slowed their fire.
The researchers hence found out that scratching does its work in the spinal cord rather than in the brain, showing that there is no itch centre in the brain. But when scratching came before the injection, it didn’t provide any relief. Somehow, the spine knows when scratching is helpful and when it isn’t!
It is Contagious!
What is more, like yawning, itching can be contagious! Physicians say that they start feeling itchy after treating patients for scabies. And researchers once gave a lecture on itching just to see if they could get their audience to feel itchy, and it worked. Hidden cameras revealed that the audience spent a lot more time scratching themselves during that lecture than during a talk on a different subject.
Consider this, in a 1948 paper in the Journal of Investigative Dermatology, Washington University School of Medicine neurophysiologist George Bishop noted that:
Scratching an itch with a violence that would cause pain elsewhere may actually be experienced as an exquisite pleasure!
The summary of that observation is that a scratch which would otherwise be painful when there is no itch, is transformed into something pleasurable when an itch is the cause! And in truth, patients with eczema have reported that they scratch not until the itch has subsided, but rather until it no longer feels good to scratch!!
So, keep this in mind the next time you scratch, that it is simply pleasurable pain.
See Also: VITILIGO: The Skin Condition You Should Know About
