According to new research being carried out at the Temple University School of Medicine (TUSM) in the United States, the same areas that respond to reward and pleasure are linked to the abilit
According to new research being carried out at the Temple University School of Medicine (TUSM) in the United States, the same areas that respond to reward and pleasure are linked to the ability of a drug known as butophanol to relieve the sensation of itching.
The research is led by Gil Yosipovitch who is the Director of the Temple Itch Center.
Why do we need this research?
For those who only experience the odd tingle, it might seem over-the-top to devote an entire center to the science of itchiness, but I for one am thrilled to hear that there is.
Having suffered with eczema and skin allergies for most of my childhood, I know how irritating and upsetting it can be to have skin problems. Something as apparently menial as itchy and sensitive skin can get in the way of simple run-of-the-mill choices such as what to wear, whether to go swimming, what suncream to use, can I pet that animal, and so on.
Chronic itching actually affects around 12 per cent of the population and is caused by skin conditions such as atopic eczema and psoriasis, but also by diseases such as lymphoma and liver failure.
In West and Central Africa, a disease called Cutaneous Filariasis is caused by thread-like nematodes (or roundworm) parasites. These are spread by biting insects like black fly and mosquitoes. The disease can also affect lymph nodes, if that is where the parasites migrate to in the body, and this is often considered the more serious disease due to the huge swellings it can cause.
However, when the parasites occupy the subcutaneous layer of the skin, just underneath the skin surface, the host is burdened with itching so severe that many are unable to work. In many African countries, this could mean that the sufferers can no longer afford to eat.
Itching is much more debilitating than it can seem on first inspection, and research into the relief of itching could dramatically improve the lives of countless people.
The findings
The findings at TUSM point to the involvement of opioid receptors in the brain. These receptors are usually recognised for their involvement in reward, addiction and feeling pain.
Reward pathways are associated with their response to pleasurable stimuli and previous studies from the centre have shown that the activation of reward in the brain is correlated with the level of pleasure and the degree of itch relief achieved from self-scratching.
The drug butorphanol stopped chronic itching that was triggered by histamine, which is a small molecule involved in allergic reactions and produced by basophils (a type of white blood cell). Butorphanol worked better for histamine mediated itching than non-histamine related itching in this study, where all cases of histamine itching were suppressed, compared to 35 per cent of non-histamine cases.
A quick note about histamines – You’ve probably heard of anti-histamines, the drug you might take for allergies such as hayfever. These help by blocking histamine receptors to hopefully relieve symptoms from the classic annoying inflammatory responses like itchy eyes, hives and sneezing.
What does this mean for the future?
The findings of the study suggest that the drug works primarily on opioid receptors to suppress the itch sensation induced by histamine, but it also has an important effect on itch pathways that do not involve histamine. Many different substances in the body cause itching, so there is still a lot to learn.
“We are in a position now to better understand the itch-scratch cycle” said Yosipovitch, in an interview with the health web site Medical Xpress. “To break the cycle from the top down, knowing here to target receptors in the brain would be a major achievement.”
There is more that needs to be understood, but the knowledge that pleasure receptors in the brain are involved in itch relief could pave the way for hundreds of potential new treatment options for people suffering with itching.
What do you think? Have your say in the comments section below.
Image:
[ Flickr / Stephen Hampshire ]
