[thedoc (OP)]

Mike Mollatt  asked the Naked Scientists:
   
Hello Chris  -
 
My wife and I listen to your show on Friday mornings here in Cape Town and are always fascinated by the depth of your knowledge and amazing explanations. I have tried to get to you "live" via the radio programme on a number of occasions, but the queued listeners with the same objective have thus far precluded such contact.
 
For many years (I'm 68)  I have wondered what causes the skin to itch suddenly (the cause not being attributable to an insect bite or "prickly heat" or even dry skin), and why it is that scratching the itching spot relieves the sensation. Such relief may be long-lasting or not........
Best wishes,
 
Mike Mollatt, Fish Hoek, Cape Town  

What do you think?

[chris]

Here are some references from other Naked Scientists programmes and questions we've tackled that deal with the physiology of itch:

1) A report on the identification of a population of itch-specific nerve cells in the skin that communicate itch-sensations to the spinal cord.

2) Scientists discover that a subset of the small-calibre nerve cells that normally signal pain are responsible for conveying itch sensations.

3) Finally, an account of the age-old question of why healing wounds itch.