New research from a world-renowned itch expert, shows that the relief derived from scratching an itch all depends on the itch’s location.
The study evaluated whether itch intensity was perceived differently at three body sites, and the correlation between pleasure and itch relief induced by scratching.
They induced itch on the ankles, forearms and backs of 18 brave volunteers by rubbing their skin with cowhage – a tropical plant infamous for the extreme itchiness it produces on contact. Itch intensity and scratching pleasurability were then assessed every 30 seconds for five minutes.
Subjects weren’t allowed to scratch their own itch. Instead, the researchers rubbed their subjects’ induced itches with a cytology brush! Probably not nearly as satisfying as scratching with a nice sharp fingernail, but more reproducible for the purposes of the study.
The researchers tested the itch-scratch response at three sites: back, forearm and ankle. Turns out scratching the ankle produced more pleasurable and longer-lasting itch relief than the other two locations.
Before you ask why the researchers chose the back, ankle and forearm to make their measurements, be reassured that this is just the start. “Future studies,” they write, “could also examine the scratching pleasurability associated with other itchy areas such as the scalp or the anogenital region.
Yosipovitch believes this research provides a better understanding of itch and how to relieve it for people who have skin disease.
“We see commonly involved areas such as the ankle and back in itchy patients with skin disorders caused by eczema or psoriasis,” he said. “We never understood why those areas were more affected, and now we better understand that itch in these areas is more intense and pleasurable to scratch.”
Whatever else they learn, the Wake Forest researchers have proven one thing: Every itch has its niche!