Anecdotal evidence has long suggested that scratching an itch, much like yawning, is something we can't resist doing if we see others doing it. Now, scientists at Wake Forest Baptist Medical Center have confirmed, in a study published in the British Journal of Dermatology, say they have confirmed, scientifically, that itching really is catching. Here, a brief guide to what the study:
What did they find out about itching?
The researchers monitored how 25 participants reacted when they saw a series of five-minute videos — some showing people scratching, others showing them "acting normally." The participants were divided into three groups: People suffering from eczema; healthy subjects who had an itch-inducing histamine applied to their arms; and another healthy group that was given a placebo. All three groups reacted the same way, scratching more when those on screen did, and scratching less when those on screen refrained. Notably, those doused with the itchy arm solution clawed themselves all over, not just on their arms.
What causes contagious itching?
Based on similar studies conducted on other primates, scientists believe this is an "inherited biological alarm" that once warned humans about potentially dangerous infections among a population. "This shows that the power of the brain is pretty extreme," says Dr. Alexandru Papoiu, one of the study's researchers. Of course, it's not the only human response that's susceptible to going viral. "The mechanisms underlying contagious itching may be similar to the ones involved in contagious yawning, a phenomenon that is still intensely studied, but not exactly clear,' said Dr. Gil Yosipovitch, who led the team.
Scientists now know that certain stimuli cause people to scratch even when there's no obvious reason to itch. The next step is to target the specific areas in the brain that produce those responses. "If we can understand the underlying mechanism and its cause," says Papoiu, "we should have a better chance to treat itch, targeting the central nervous system stations involved."