Scratching is the natural response to itch and, by definition, inseparable from it. The act of scratching not only diminishes itch, but also can be rewarding and addictive. In December, there was a study done that aimed to visualize in real-time by brain imaging the core mechanisms of the itch- scratch cycle when scratching was preformed by subjects themselves.
For a long time, itching was long overshadowed by pain in both research and treatment, and was even considered just a mild form of pain. But times have changed. Dr. Lynn Cornelius, chief of the dermatology division at Washington University School of Medicine stated that itching “used to be lumped together with pain.” But now, she said, “there is more interest in itching and in sorting out its different types, and more research money being spent on it.” Research has found nerves, molecules and cellular receptors that are specific for itching and set it apart from pain. The worry isn’t so much about nasty mosquito bites and poison ivy, in which skin cells release histamine, causing nerves in the skin to fire off signals to the spinal cord and brain. But rather they are looking at the unending wretchedness caused by chronic itching — the kind that won’t go away, and very often resists remedies like antihistamines and cortisone cream.
Researchers say that before, the focus was on finding new age antihistamines, but now it’s on new molecular and cellular targets to develop new therapies. Some breakthrough work happened when a Washington University team, led by Zhou-Feng Chen, was studying receptors on mice. The group was the first to find a receptor in the spinal cord that was specific for itching, called gastrin-releasing peptide receptor, or GRPR. The discovery helped to prove that signals for itching and pain travel on different pathways. In an interview, Dr. Chen said that mice without the receptor — or with the receptor blocked by a drug — did not itch. Dr. Chen additionally pointed out that the receptor is also present on humans and that it’s possible to develop a drug that would block it.
This is definitely an interesting field of research and is gaining lots of popularity as itching research and treatment centers have opened: Temple’s in September, in Philadelphia, and Washington University’s Center for the Study of Itch. Most of us go throughout our days without thinking about how many times we get an itch, or about the amount of people suffering from a chronic itching disorder. I’m excited to see as more and more studies come out about the itch-scratch cycle.
Posted by Samuel Ustayev (3)