研究发现：挠痒也可以传染

If ever you have felt a previously undetected itch when you notice someone else scratching, you are not Alone. The phenomenon of the "contagious itch" has been studied for the first time by a team of US researchers who found that itching can be visually transmitted。

Dermatologists compared 14 healthy subjects with 11 patients who had the skin condition atopic dermatitis (AD). The healthy subjects had a histamine solution, which was designed to make them itch. Others had a harmless salt solution applied. All of the 25 test subjects were then shown five-minute video clips of people scratching。

The test subjects scratched twice as much when watching the videos of someone else scratching, compared to the video of the person doing nothing, in both the healthy subjects and those with AD. The AD sufferers scratched more frequently and intensely than the healthy subjects。

That means that itching, while at times a genuine physical sensation can also be activated by the power of the brain's suggestion alone. Simply watching someone scratching - or even reading about it - can provoke the sensation。

The findings appear in The British Journal of Dermatology。

看到别人抓耳挠腮，随即发现自己也有了挠痒痒的冲动，这种情况不只在你一人身上发生。日前美国研究人员首次研究了“传染性瘙痒”现象，并发现“瘙痒”感觉可以视觉传染。

皮肤病学家将受试对象分为两组，一组是14个健康个体，一组则是有特应性皮炎的11位患者。健康者服用了可以致痒的组胺溶液，其他人则服用了无害的盐水。接下来25个受试对象均观看了5分钟的描绘人们挠痒的视频片段。

研究人员发现，无论是健康人还是特应性皮炎患者，与观看了描绘人们什么都没做的视频的受试对象相比，观看了“挠痒”视频的收拾对象挠痒次数是前者的两倍。而特应性皮炎患者比健康人士挠痒的频率更高、程度更严重。

这就意味着，瘙痒有时确实是实实在在的生理体验，但也可以单凭大脑暗示被激活。只要看别人挠痒——或者仅仅是读到关于挠痒的文字——这种“瘙痒”感便会油然而生。

研究结果刊登于《英国皮肤病学杂志》。