Everybody itches, and our innate reaction is to scratch. People find it debilitating and annoying because sometimes an itch arises for no apparent reason, but it could also serve as a warning. The itch sensation has long been a mystery, but today, researchers have discovered a clue that could demystify this phenomenon. In a new study using mice, researchers have identified a chemical that sends a message to the brain from the neurons that detect itch.
Dr Ethan Lerner, an associate professor of Dermatology at Harvard medical School, told Journal Science that some itches were difficult to manage. People with eczema and those on dialysis for kidney develop severe itching. Dr Lerner announced that scientists had found that scratching has evolved as a natural defense against parasite trying to burrow through the skin.
The Root of Itch Discovered
Dr Mark Hoon and Santosh Mishra of the National Institute of Dental and Craniofacial Research in Bethesda, Md., may have discovered a new molecule that is responsible for itching. The molecule called Nppb or natriuretic polypeptide B was tested on mice, along with other neurotransmitters.
In the study, the mice were injected with Nppb on the skin, and they barely scratched. When they injected the molecule into the part of the spinal cord called dorsal horn, the mice immediately start scratching. Evidently, the genetically engineered mice who do not have the neurotransmitter did not scratch – National Geographic and Journal Science.
Dr Glenn Geisler, Jr., a neuroscientist at the University of Minnesota, Twin Cities, believes that the new study is a big step forward towards demystifying the itch mystery, and that we are now beginning to understand the mechanisms that may lead to better treatments.
Mice were used because they have similar biology to humans, and the finding can help researchers understand how and why people itch. He added that the neurons that have fibers in the skin are responsible for detecting not only itching, but pain and temperature. Dr Hoon finally comments that although this study can lead to more effective treatments, it is not good to block Nppb because it may have negative ramifications.
What Does Itching Indicate?
According to a Yale scientific study, eczema is the number one cause of itching. Approximately, 18 million Americans suffer from atopic or chronic form of eczema, of which 20 percent are children and 10 percent suffer from prolonged itching. The skin disorder is usually treated with topical steroid creams and moisturizers. Other causes include insect bites, Psoriasis, skin allergies, parasites; mosquito bites, and other forms inflammatory responses. Too much scratching may cause the upper layer of skin to lose its protective properties and the nerve fibers just below the skin can be over activated, thereby magnifying the itch.
Dr Lerner says that chronic health conditions can cause itching, such as cancer and those who are undergoing dialysis for kidney disorder. Itching is not as bad as you might think as it serves as a warning mechanism that something is wrong in the body. However, scientists also warn that scratching can be habit forming, called “itch–scratch” cycle.
As of today, there are no medical means to treat itching, nevertheless, it’s mystery is increasingly becoming demystified.
Written by: Janet Grace Ortigas