%0 Journal Article %T A Test每Retest Reliability Study of Human Experimental Models of Histaminergic and Non-histaminergic Itch %A Anne-Kathrine R. Sˋrensen %A Gebbie A.R. Nielsen %A Hjalte H. Andersen %A Jesper Elberling %A Lars Arendt-Nielsen %A Marianne S. Mˋlgaard %A Pernille Stilling %A Shellie A. Boudreau %J - %@ 1651-2057 %D 2017 %R 10.2340/00015555-2502 %X Numerous exploratory, proof-of-concept and interventional studies have used histaminergic and non-histaminergic human models of itch. However, no reliability studies for such surrogate models have been conducted. This study investigated the test每retest reliability for the response to histamine- and cowhage- (5, 15, 25 spiculae) induced itch in healthy volunteers. Cowhage spiculae were individually applied with tweezers and 1% histamine was applied with a skin prick test (SPT) lancet, both on the volar forearm. The intensity of itch was recorded on a visual analogue scale and self-reported area of itch was assessed 5 and 10 min after itch provocation. Reliability of the evoked itch (area under the curve and peak intensity) was assessed by the coefficient of variation (CV), intra-class correlation coefficient (ICC), and sample size estimation for parallel and cross-over designs. Cowhage (ICCˋ=ˋ0.57每0.77, CVbetweenˋ=ˋ97%, CVwithinˋ=ˋ41%) and histamine: (ICCˋ=ˋ0.83每0.93, CVbetweenˋ=ˋ97%, CVwithinˋ=ˋ20%) exhibited moderate-to-excellent intra-individual reliability and moderate inter-individual reliability for the itch intensity. For a test每retest observation period of one week, SPT-delivered histamine and application of cowhage-spiculae are reproducible human models of itch. The high inter-individual and low intra-individual variability suggests cross-over designed studies when applicable. %U http://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2502