allodynia

   The term allodynia comes from the Greek words allos (other) and odunè (pain), translating loosely to 'other pain'. It is used to denote a condition characterized by pain due to a stimulus that does not normally evoke pain. Patho-physiologically, allodynia involves a change in the quality of nociception, whether tactile, thermal, or of any other origin, which is associated with an alteration in the specificity of the tactile sensory modality. Some examples of allody-nia are cold allodynia, heat allodynia, and tactile allodynia. The term allodynia is used in opposition to the term * hyperalgesia, which represents an augmented response of pain receptors to painful (as opposed to normal) stimuli. Conceptually, allodynia and hyperalgesia should not be confused with other pain syndromes, such as * algopsychalia, * dysaesthesia, * paraesthesia, * hyperpathia, and * hallucinated pain. The issue whether pain can also be experienced in a hallucinated form is a knotty philosophical issue.

   References

   Coutaux, A., Adam, F., Willer, J.C., Le Bars, D. (2005). Hyperalgesia and allodynia: Peripheral mechanisms. Joint Bone Spine, 72, 359—371.

   Canavero, S., Bonicalzi, V. (2007). Central pain syndrome. Pathophysiology, diagnosis and management. Cambridge: Cambridge University Press.