Everybody itches, and it is an innate reaction to scratch. People find it debilitating and annoying because sometimes a skin irritation arises for no apparent reason, but it could also serve as a warning. The itching 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 irritations.
Dr. Ethan Lerner, an associate professor of dermatology at Harvard Medical School, told Journal Science that some skin irritations are difficult to manage. People with eczema and those on dialysis, develop severe itching. Dr. Lerner announced that scientists have found that scratching has evolved as a natural defense against parasites trying to burrow through the skin.
The Root of Itch Discovered
Drs. 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 and they barely scratched. When the molecule was injected into the part of the spinal cord referred to as, dorsal horn, the mice immediately started scratching. Evidently, the genetically engineered mice who did not have the neurotransmitter did not scratch, according to 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 toward demystifying the itch mystery and that researchers are now beginning to understand the mechanisms that may lead to better treatments.
Mice were used because their biology is similar to humans and the finding could help researchers understand how and why people experience prickly skin irritations. Geisler, Jr. added that the neurons which have fibers in the skin are responsible for detecting, not only itching, but pain, and temperature. Hoon 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 an atopic, or chronic form of eczema, of which 20 percent are children and 10 percent suffer from prolonged irritation. The skin disorder is usually treated with topical steroid creams and moisturizers. Other causes can 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. The nerve fibers, just below the skin, can be over activated, thereby, magnifying the irritation.
Lerner says that chronic health conditions can cause irritation of the skin, such as cancer and those who are undergoing dialysis for a kidney disorder. Itching is not as bad as one 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 and is called the “itch–scratch” cycle.
As of today, there are no medical means to treat itching, nevertheless, its mystery is increasingly becoming demystified.
By Janet Grace Ortigas