Attenuation of experimental pruritus and mechanically evoked dysesthesiae in an area of cutaneous allodynia

Citation
Sj. Brull et al., Attenuation of experimental pruritus and mechanically evoked dysesthesiae in an area of cutaneous allodynia, SOMAT MOT R, 16(4), 1999, pp. 299-303
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
SOMATOSENSORY AND MOTOR RESEARCH
ISSN journal
0899-0220 → ACNP
Volume
16
Issue
4
Year of publication
1999
Pages
299 - 303
Database
ISI
SICI code
0899-0220(1999)16:4<299:AOEPAM>2.0.ZU;2-5
Abstract
We investigated the effects of tactile allodynia on the itch and mechanical ly evoked dysesthesiae produced by an intradermal injection of histamine in human volunteers. After an intradermal injection of capsaicin into the vol ar surface of one forearm, there developed an area of tactile allodynia to stroking and hyperalgesia to pricking the skin. Histamine was then injected simultaneously into the area of allodynia (experimental arm) and into the opposite forearm (control arm). Magnitude estimates of itch were obtained e very 15 s for 5 min, and the areas of cutaneous hyperalgesia (pricking-evok ed pain), alloknesis (stroking-evoked itch), hyperknesis (pricking-evoked i tch) and wheal and flare were measured. The areas of wheal and flare were n ot significantly different on the two arms. The magnitude of itch and the a reas of hyperknesis and alloknesis developed normally on the control arm bu t were absent or greatly reduced on the experimental arm. Thus, both the it ch and the alloknesis and hyperknesis normally induced by histamine were ab sent or greatly reduced when histamine was injected in an area of capsaicin -induced allodynia. These results are compatible with the hypothesis that a ctivity in capsaicin-sensitive, nociceptive primary afferent neurons evokes a central neuronal inhibitory process that prevents or reduces the itch an d mechanically evoked dysesthesiae normally produced by an intradermal inje ction of histamine.