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Scratching away at the mystery of itch

Published: 
Thursday, January 30, 2014
Your Daily Health
Scientists now have several theories about the odd connection between pain and itch.

The sensation of feeling itchy is pretty universal, and yet scientists still don’t completely understand the complex processes that give us the urge to scratch.

 

Itching can be annoying, but like pain, a little bit can be a good thing. Itching can help people learn to avoid dangers such as mosquitoes carrying malaria, or poison ivy. But many people suffer from chronic itch, which has no direct cause and can be a debilitating condition with few options for relief.

 

“When people hear about itch, they think about a mosquito bite or chicken pox, which is irritating but very temporary,” said Diana Bautista, a cell and developmental biologist at the University of California, Berkeley, who wrote an article summarising our current understanding of itch, published on Tuesday in the journal Nature Neuroscience.

 

Bautista said people often laugh when she tells them she studies itch. But “from a clinical perspective, chronic itch is a really widespread problem, and incredibly difficult to treat,” she told LiveScience. 

Itch, or ouch?

 

Like the feelings of touch, temperature and pain, itching involves a complex system of molecules, cells and circuits reaching from the skin into the brain. Most over-the-counter treatments for itching target histamine, a compound involved in inflammation. But many kinds of itch can’t be treated with antihistamines or other available treatments.

 

Skin conditions such as eczema and psoriasis, systemic conditions including multiple sclerosis, and even some cancers, can all lead to chronic itch, which affects about ten per cent of the world’s population at some point during their lives, Bautista said.