%0 Journal Article
%T Antipruritic Effect of Cold-induced and Transient Receptor Potential-agonist-induced Counter-irritation on Histaminergic Itch in Humans
%A Amalie Randers
%A Amalie Simoni
%A Anne Jerwiarz
%A Camilla Melholt
%A Hjalte H. Andersen
%A Jesper Elberling
%A Lars Arendt-Nielsen
%A Sigurd D. Hilborg
%J -
%@ 1651-2057
%D 2017
%R 10.2340/00015555-2447
%X A frequent empirical observation is that cold-induced counter-irritation may attenuate itch. The aim of this randomized, single-blinded, exploratory study was to evaluate the counter-irritation effects of cold-stimulation and topical application of transient receptor potential TRPA1/M8-agonists (trans-cinnamaldehyde/L-menthol, respectively), on histamine-induced itch, wheals and neurogenic inflammation in 13 healthy volunteers. Histamine 1% was applied to the volar forearms using skin prick-test lancets. Recorded outcome-parameters were itch intensity, wheal reactions, and neurogenic inflammation (measured by laser-speckle perfusion-imaging). Homotopic thermal counter-irritation was performed with 6 temperatures, ranging from 4¡ãC to 37¡ãC, using a 3£¿¡Á£¿3-cm thermal stimulator. Chemical ¡°cold-like¡± counter-irritation was conducted with 40% L-menthol and 10% trans-cinnamaldehyde, while 5% doxepin was used as a positive antipruritic control/comparator. Cold counter-irritation stimuli from 4¡ãC to 22¡ãC inhibited itch in a stimulus-intensity-dependent manner (p£¿<£¿0.05) and, to a lesser extent, also wheal reactions and neurogenic inflammation. Chemical ¡°cold-like¡± counter-irritation with both L-menthol and trans-cinnamaldehyde had antipruritic efficacy similar to doxepin (p£¿<£¿0.05). Cold-induced counter-irritation had an inhibitory effect on histaminergic itch, suggesting that agonists of cold transduction receptors could be of potential antipruritic value.
%U http://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2447