Antipruritic Effect of Cold-induced and Transient Receptor Potential-agonist-induced Counter-irritation on Histaminergic Itch in Humans

Acta Derm Venereol. 2017 Jan 4;97(1):63-67. doi: 10.2340/00015555-2447.

Abstract

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°C to 37°C, using a 3 × 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°C to 22°C 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.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acrolein / analogs & derivatives*
  • Acrolein / pharmacology
  • Antipruritics / pharmacology*
  • Cold Temperature*
  • Doxepin / pharmacology
  • Female
  • Healthy Volunteers
  • Histamine / immunology*
  • Histamine Antagonists
  • Humans
  • Male
  • Menthol / pharmacology*
  • Pruritus / immunology*
  • Pruritus / prevention & control*
  • Single-Blind Method
  • Transient Receptor Potential Channels / agonists*
  • Treatment Outcome
  • Young Adult

Substances

  • Antipruritics
  • Histamine Antagonists
  • Transient Receptor Potential Channels
  • Menthol
  • Doxepin
  • Acrolein
  • Histamine
  • cinnamaldehyde