Encyclopedia of Pain

2007 Edition

Allodynia and Alloknesis

  • Robert H. LaMotte
Reference work entry
DOI: https://doi.org/10.1007/978-3-540-29805-2_154


Alloknesis and Allodynia


Allodynia and alloknesis are abnormal sensory states wherein normally innocuous stimuli elicit unpleasant sensations or aversive responses.

 Allodynia is the  nociceptive sensation or aversive response evoked by a stimulus that is normally non-nociceptive (“allo” – “other”; “dynia” - pain). For example, a light stroking of the skin produced by the lateral motion of clothing, or the heat produced by the body are stimuli that do not elicit nociceptive sensations or responses under normal circumstances. However, these stimuli may become nociceptive after a cutaneous injury produced, for example, by sunburn. In contrast,  hyperalgesia is defined as the abnormal nociceptive state in which a normally painful stimulus such as the prick of a needle elicits a greater than normal duration and/or magnitude of pain.

 Alloknesis is the itch or  pruriceptive sensation (from the Latin word prurire, to itch) or scratching behavior evoked by a stimulus that...

This is a preview of subscription content, log in to check access.


  1. 1.
    Atanassoff PG, Brull SJ, Zhang JM et al. (1999) Enhancement of experimental pruritus and mechanically evoked dysesthesias with local anesthesia. Somatosen Mot Res 16:299–303Google Scholar
  2. 2.
    Brull SJ, Atanassoff PG, Silverman DG et al. (1999) Attenuation of experimental pruritus and mechanically evoked dysesthesias in an area of cutaneous allodynia. Somatosen Mot Res 16:291–298Google Scholar
  3. 3.
    Graham DT, Goodell H, Wolff HG (1951) Neural mechanisms involved in itch, “itchy skin,” and tickle sensations. J Clin Invest 30:37–49Google Scholar
  4. 4.
    Handwerker HO, Forster C, Kirchoff C (1991) Discharge properties of human C-fibres induced by itching and burning stimuli. J Neurophysiol 66:307–315Google Scholar
  5. 5.
    Handwerker HO (1992) Pain and allodynia, itch and alloknesis: an alternative hypothesis. Am Pain Soc J 1:135–138Google Scholar
  6. 6.
    LaMotte RH, Shain CN, Simone DA et al. (1991) Neurogenic hyperalgesia: Psychophysical studies of underlying mechanisms. J Neurophysiol 66:190–211Google Scholar
  7. 7.
    LaMotte RH (1992) Subpopulations of “nocifensor neurons” contributing to pain and allodynia, itch and alloknesis. Amer Pain Soc J 1:115–126Google Scholar
  8. 8.
    Magerl W, Westerman RA, Mohner B et al. (1990) Properties of transdermal histamine iontophoresis: differential effects of season, gender and body region. J Invest Dermatol 94:347–352Google Scholar
  9. 9.
    Nilsson H-JA, Levinsson A, Schouenborg J (1997) Cutaneous field stimulation (CFS) – a new powerful method to combat itch. Pain 71:49–55Google Scholar
  10. 10.
    Schmelz M, Schmidt R, Bickel A et al. (1997) Specific C-receptors for itch in human skin. J Neurosci 17:8003–8008Google Scholar
  11. 11.
    Schmelz M, Schmidt R, Weidner C et al. (2003) Chemical response pattern of dofferent classes of C-nociceptors to pruritogens and algogens. J Neurophysiol 89:2441–2448Google Scholar
  12. 12.
    Shelley WB, Arthur RP (1957) The neurohistology and neurophysiology of the itch sensation in man. Arch Dermatol 76:296–323Google Scholar
  13. 13.
    Simone DA, Oh U, Sorkin LS et al. (1991a) Neurogenic hyperalgesia: Central neural correlates in responses of spinothalamic tract neurons. J Neurophysiol 66:228–246Google Scholar
  14. 14.
    Simone DA, Alreja M, LaMotte RH (1991b) Psychophysical studies of the itch sensation and itchy skin (“alloknesis") produced by intracutaneous injection of histamine. Somatosens Motor Res 8:271–279Google Scholar
  15. 15.
    Tuckett RP, Wei JY (1987) Response to an itch-producing substance in cats, II. Cutaneous receptor populations with unmyelinated axons. Brain Res 413:87–94Google Scholar
  16. 16.
    Ward L, Wright E, McMahon SB (1996) A comparison of the effects of noxious and innocuous counterstimuli on experimentally induced itch and pain. Pain 64:129–138Google Scholar
  17. 17.
    Wei JY, Tuckett RP (1991) Response of cat ventrolateral spinal axons to an itch-producing stimulus (cowhage). Somatosens Motor Res 8:227–239Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Robert H. LaMotte
    • 1
  1. 1.Department of AnesthesiologyYale School of MedicineNew HavenUSA