An itch is a sensation felt on an area of skin that causes a person or animal to desire to scratch that area.

It is a distressing symptom that can cause discomfort.

Scratching may cause breaks in the skin that may result in infection.

Itching can be related to anything from dry skin to undiagnosed cancer.

The central chemical involved in itching is histamine, a molecule released by mast cells in the skin.

Histamine is the chemical that causes the itch and reddening when bitten by insects.

It binds to local nerve endings on specific receptors.

An itch from cutaneous (skin-related) stimuli, such as movement of small hairs on the body, is transmitted along the same pathway as pain..

For more information about the topic Itch, read the full article at Wikipedia.org, or see the following related articles:

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Got An Itch? New Study Shows How Scratching May Relieve It (April 29, 2009) — Every dog and cat knows that scratching relieves an itch. But for ages, not even neuroscientists knew why. Now, a new study shows that scratching turns off activity in spinal cord nerves that ...  > read more

Itch-specific Neurons Identified In Mice Offers Hope For Better Treatments (August 8, 2009) — Researchers have discovered that itch-specific neurons exist in mice, and their studies suggest that itch and pain signals are transmitted along different pathways in the spinal cord. The researchers ...  > read more

Pain And Itch Responses Regulated Separately (November 25, 2008) — Historically, scientists have regarded itching as a less intense version of the body's response to pain, but researchers have now determined that pain and itch actually are regulated by different ...  > read more

Scratch No More: Gene For Itch Sensation Discovered (July 25, 2007) — Itching for a better anti-itch remedy? Your wish may soon be granted now that scientists have identified the first gene for the itch sensation in the central nervous system. The discovery could ...  > read more

Giving In To The Urge To Scratch: Researchers Find Not All Itches Created Equal (December 8, 2006) — Different reactions in the brain to two common allergy triggers -- allergens (pollen and dust) and histamine (allergy cells within the body caused by foods, drugs or infection) -- may shed some light ...  > read more

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