Itching to Know
Jun 06, 2013 10:46PM ● Published by Anonymous
Quite simply, an itch begins thanks to an external stimuli landing on your skin. This could be your clothing, an insect, or even dust. Once this stimuli make landfall, your skin receptors become irritated. Your brain then gets the message from your skin to scratch. After you spend a few seconds scratching, your brain senses the relief and stops sending the scratch alert—until it comes back and the process begins again.
Those receptors in the skin are the real curiosity. That’s why researchers have been studying them for decades. And they have long suspected a connection between those itchy nerve endings and ones associated with pain sensations. Since the same fibers sending the itchy-signal to the brain also send the pain signal, many believe that itching is another form of pain.
Researchers at Johns Hopkins and Yale University, however, may recently have found the evidence to disprove that connection. In their itch study, “itch-specific” nerves were found in the body. Using lab mice exposed to pain stimuli and itch stimuli (the less detail here the better, but it had to do with pain-inducing chemicals), the research team concluded there was a distinct difference between the itch- and pain-sensitive nerves. Pain and itching evoked two completely different bodily responses—pain caused the mice to withdraw, while itching caused them to scratch.
Pain and itching not related, huh? Anyone who has experienced an itch right in the middle of the back where they can’t possibly reach might beg to differ. —Gina Oursler
The Latest Buzz about Hives
In the same diagnostic ballpark, an international team of researchers (including our neighbors at Johns Hopkins again) has recently found an effective treatment for people chronically afflicted with hives and severe rashes. Interestingly, the discovery was found in an unlikely place—a drug already on the market for a completely different ailment. A once-a- month, high-dose injection of the drug Omalizumab (commonly used to treat allergic asthma) has proven highly effective in treating teens and adults with serious hives and rashes. Three-hundred and twenty-three patients in 55 medical centers, for whom standard antihistamine therapy did not work, were given the drug treatment.
All participants (mostly women between the ages of 12 and 75) had chronic hives/rashes for at least six months. The study ran from 2009 to 2011 and used the standard randomly assigned placebo versus real drug protocol. Neither the researchers nor
the participants knew who was getting which. The results offer substantial evidence that this treatment not only works, but does so more safely than other drug alternatives such as corticosteroids, with their significant side effects. This is a potentially life-altering discovery for the three million or so people who suffer from chronic idiopathic urticaria (CIU)—the almost daily occurrence of wheals and itching for at least six weeks with no obvious cause. It is a major affliction that can cause substantial disability. The fact that help may be within reach thanks to an existing asthma medicine should make us all breathe easier.
In yet another drug-was-meant-for-someother- condition discovery, researchers at the University of Washington School of Medicine have uncovered a potentially groundbreaking treatment for the misery of macular degeneration, an eye disease that causes vision loss in the center of your fi eld of vision. Scientists have drawn a connection between high cholesterol levels and macular degeneration. Tests on mice and humans, published in the Cell Metabolism journal, showed that immune cells became destructive when they were clogged with fat. The physicians treated the condition with eye drops made from a drug originally created to lower cholesterol.
Macular degeneration is primarily an agerelated condition. With the explosion of senior boomers beginning, and with 200,000 new cases of macular degeneration diagnosed each year, the timing of a discovery like this could have a dramatic impact. Research and results, however, are at a very early stage; so we should be cautiously optimistic.--S.H.