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Scientists think they may have the answer for your itch

If a random itch often keeps you awake at night tossing and turning in bed, scientists may finally have some good news for you.

They have discovered that a drug already in use to treat arthritis helps to relieve the annoying urge to scratch relentlessly.

Tofacitinib, when taken twice daily, helped five patients with severe itches from unknown causes make ‘dramatic’ improvements, a study showed.

The Washington University, St Louis, findings, dubbed ‘encouraging’, help to identify the mysterious roots of chronic itching.

Scientists have discovered that a drug already in use to treat arthritis helps to relieve the annoying urge to scratch relentlessly

How many people have itches?

Chronic itch affects up to 15 percent of the population, figures suggest, and is most often caused by eczema and psoriasis.

However, cases of chronic itching for which there are no known causes are puzzling and among the most difficult to treat. 

Study author Dr Brian Kim said: ‘These patients often itch day and night, and for some of them, the urge to scratch never goes away.

‘Although this was a small study, the patients taking tofacitinib experienced dramatic improvements in terms of their itch, allowing them to sleep, stop scratching and return to living more productive lives.’ 

He added: ‘Obviously, we’ll need to do a larger study, but the early results are very encouraging.’ 

How was the study carried out? 

For the study, published in the journal Cell, five patients with chronic idiopathic pruritus – an itch of an unknown cause – were monitored.


While it may not be the most pleasant feeling, the itch sensation is an important protective mechanism for animals.

But chronic itching, often seen in patients with skin and liver diseases, remains a challenging problem to treat.

Now, a new study has shed light on the brain mechanism behind itching – which experts say could help to develop a treatment for chronic itching. 

Researchers from the Institute of Neuroscience of the Chinese Academy of Sciences looked at the precise pathway from the spinal cord to the brain.

As well as tofacitinib, they were given other anti-inflammatory drugs to curb their symptoms. However, none of the others proved successful.

Although the patients with chronic idiopathic pruritus usually didn’t have rashes on their skin, they still had severe and debilitating itch. 

What did they find? 

But when taking tofacitinib, those patients experienced, on average, almost an 80 percent improvement in their itch severity. 

In tests on both mice and humans, the team of researchers were able to identify the cause of chronic itches.

They showed that sensory neurons, which carry messages of pain to the brain, are activated by an immune signalling molecule called interleukin-4 (IL-4).

It jump starts the process of itching in both patients of inflammation-related skin conditions, and those of unknown causes.

How does the drug work? 

The researchers said IL-4 stimulates a key protein within nerve cells – JAK1 – that is a critical component of chronic itching.

That finding led the team to suspect that JAK1 may be a uniquely sensitive target for multiple types of itch, even itching of unknown cause.  

Tofacitinib, a known JAK inhibitor, blocks this protein and can stop the need to relentlessly scratch to get rid of an itch, the researchers said.