TY - JOUR

T1 - A Test–Retest Reliability Study of Human Experimental Models of Histaminergic and Non-histaminergic Itch

AU - Andersen, Hjalte H.

AU - Sørensen, Anne Kathrine R.

AU - Nielsen, Gebbie A.R.

AU - Mølgaard, Marianne S.

AU - Stilling, Pernille

AU - Boudreau, Shellie A.

AU - Elberling, Jesper

AU - Arendt-Nielsen, Lars

PY - 2017/2/1

Y1 - 2017/2/1

N2 - 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–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 (ICC=0.57– 0.77, CVbetween =97%, CVwithin =41%) and histamine: (ICC=0.83–0.93, CVbetween =97%, CVwithin =20%) exhibited moderate-to-excellent intra-individual reliability and moderate inter-individual reliability for the itch intensity. For a test–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.

AB - 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–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 (ICC=0.57– 0.77, CVbetween =97%, CVwithin =41%) and histamine: (ICC=0.83–0.93, CVbetween =97%, CVwithin =20%) exhibited moderate-to-excellent intra-individual reliability and moderate inter-individual reliability for the itch intensity. For a test–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.

KW - Cowhage

KW - Histamine

KW - Itch

KW - Itch models

KW - Reliability

KW - Test–retest

U2 - 10.2340/00015555-2502

DO - 10.2340/00015555-2502

M3 - Journal article

C2 - 27377123

AN - SCOPUS:85011949020

VL - 97

SP - 198

EP - 207

JO - Acta Dermato-Venereologica

JF - Acta Dermato-Venereologica

SN - 0001-5555

IS - 2

ER -