Stop scratching! It’s better to stroke an itch

NEXT time you have an irritating itch, try stroking it.

Scientists have discovered that stroking an itch triggers the same nerve activity as scratching it – but doesn’t damage skin.

For their study, the researchers injected mice with an itch-inducing chemical and recorded how their nerve cells responded.

They then stroked the mice with different objects and varying strength. Stroking was found to inhibit the itch sensation by activating nerve cells called low-threshold mechanoreceptors (LTMRs), which relieve the feeling.

The researchers, from the University of Miami, also found that mice stroked with wider, stronger objects had a higher number of LTMRs activated.

Scratching an itch actually causes a temporary pain sensation, the scientists say, which eclipses the feeling of the itch. On the other hand, stroking produces a touch sensation that helps to relieve the feeling without causing damage. Scratching skin can lead to problems such as bleeding, which is why stroking may be better.

Previous research has indicated that stroking works for human itches.

A third of people suffering from chronic itch have said rubbing their skin helped relieve the feeling. And many patients suffering from hives rub rather than scratch.

The latest study, published in the Journal of Neuroscience, reads: ‘Rubbing or stroking of the skin is commonly used to relieve itch in sensitive areas like the eyes or nose and is also frequently used by chronic itch patients. Rubbing or stroking the skin activates LTMRs. This study has shown that gentle skin stroking can reduce itch signalling in the spinal cord.’

The itch sensation is technically known as pruritus. It is thought to have evolved as a way to protect skin from parasites and stop the build-up of dead cells.