Scientists discover major cause of itchiness – and it could lead to new drugs for eczema

Scientists could be on the verge of a medical breakthrough if they want to eliminate the itching from eczema.

Until now, experts believed that the itching was caused by inflammation of the skin.

But researchers at Harvard University have discovered that the process that causes the overwhelming desire to scratch is separate from the cause of eczema itself, medically known as atopic dermatitis.

The scientists identified staphylococcus aureus, a common type of skin bacteria, as the bacteria responsible.

They believe that with a small adjustment, an already available treatment – ​​vorapaxar – can help break the vicious circle of eczema.

The pill, which is used to reduce the risk of heart attacks and strokes by preventing blood clots, has been approved in the US but not in the UK.

In one study, experts took skin from both arms of 13 people with eczema and 14 'healthy participants'.

They then exposed mice to Staphylococcus aureus, causing them to experience intense itching that worsened over several days and led to skin damage.

The team modified different versions of the staphylococcus aureus microbe to find out which enzymes were responsible for the itch.

Through a process of elimination, they discovered that the enzyme, V8 protease, was responsible.

Published in the magazine CellResearchers also found that this enzyme interacts directly with nerve cells in the skin, which send a signal to the brain, triggering the urge to scratch.

Liwen Deng, a postdoctoral researcher at Harvard University, said The Sunday times: 'We tested in mice whether we could block the (nerve) receptor and reduce itching. We found it to be very effective.”

Isaac Chiu, associate professor of immunology at Harvard Medical School, added: 'These drugs block the receptor on platelets that are involved in blood clotting.

'We found that itching can be directly caused by a bacterial pathogen – staphylococcus aureus – a common microbe found in about 30 percent of people, mainly in the nose.'

He said: 'Itching is not just in our heads. It is caused by specific nerves that send signals to the brain.

'Itching is actually nice if you can scratch it. But that then causes more damage to the skin, causing inflammation and perhaps allowing bacteria to further cause the itching.

'So it is a vicious circle that reduces the quality of life of some patients.'

Eczema is a group of inflammatory skin conditions that cause itching, dry skin, rashes, flaky patches and infections and affects up to 25 percent of the population.

The condition can worsen to the point of becoming disabling, with inflamed skin all over the body.

Patients may experience burning sensations or need to wrap the affected areas in bandages. It can also lead to stress and depression.

At least one in ten children will develop eczema at some point, but they will usually grow out of it as their immune systems develop.

It is believed to occur in people with a common genetic mutation that leads to very dry skin.

Symptom flare-ups can also be related to allergies or caused by certain soaps or foods.

Dermatologists will usually first prescribe creams and washes to tackle dry skin, and steroid creams to reduce swelling and redness.

If these are not effective, immunosuppressants such as cyclosporine or methotrexate are given.

These work by inhibiting certain parts of the immune system that cause inflammation, but can negatively affect immunity and the liver.