Investigation of a New Human Model for Itch

Characterization of New Human Models of Non-histaminergic Itch and Their Interaction With the TRPM8 Receptor

This third sub-project aims to evaluate the interaction between the TRPM8 receptor and pruritus by studying the anti-pruritic effect of TPRM8-agonist L-menthol on histaminergic and non-histaminergic itch induced using three different pruritogens: histamine, cowhage and papain.

Study Overview

• Status: Completed
• Conditions: Itch
• Intervention / Treatment: Other: Cowhage; Other: Papain; Other: Histamine; Other: L-menthol

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Nordjylland
    • Aalborg, Nordjylland, Denmark, 9229
      • Aalborg University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Healthy men and women
• 18-60 years
• Speak and understand English

Exclusion Criteria:

• Pregnancy or lactation
• Drug addiction defined as any use of cannabis, opioids or other addictive drugs
• Previous or current history of neurological, dermatological, immunological musculoskeletal, cardiac disorder or mental illnesses that may affect the results (e.g. neuropathy, muscular pain in the upper extremities, etc.).
• Lack of ability to cooperate
• Current use of medications that may affect the trial such as antihistamines, antipsychotics and pain killers, as well as systemic or topical steroids.
• Skin diseases
• Moles, scars or tattoos in the area to be treated or tested.
• Hypersensitivity to papaya and mango fruit, cashew nuts, rubber latex
• Consumption of alcohol or painkillers 24 hours before the study days and between these
• Acute or chronic pain
• Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical trials)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Study group

Other: Cowhage; Cowhage spicules are 1-2 mm in length and have a diameter of 1-3 μm. The spicules are inserted by gently rubbing 30-35 spicules into a 1 cm diameter skin area.; Other: Papain; Papain will be applied using cowhage spicules inactivated by heat; Other: Histamine; To deliver histamine, standard allergy skin prick test (SPT) lancets are applied; Other: L-menthol; A 1 mL aliquot is dispensed onto a 2,5 × 2,5 cm cotton pad and placed on a 6 × 6 cm sheet of medical tape.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	After 15 minutes
Measuring itch intensity by computerized Visual Analog Scale Scoring	We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable	For 15 minutes
Measuring pain intensity by computerized Visual Analog Scale Scoring	We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".	For 15 minutes
Measuring Alloknesis	Alloknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 milliNewton of force).	15 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of Cold Detection Thresholds (CDT)	The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.	15 minutes
Measurement of Cold PainThresholds (CPT)	The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.	15 minutes
Measurement of Heat Pain Thresholds (HPT)	The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.	15 minutes
Measurement of Warm Detection Thresholds (WDT)	The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.	15 minutes
Measurement of Pain to Supra-threshold Heat Stimuli	The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.	15 minutes
Measurement of Mechanical Pain Thresholds (MPT)	This test is conducted using a pin-prick set.	15 minutes
Measurement of Mechanical Pain Sensitivity (MPS)	This test is conducted using a pin-prick set.	15 minutes
Touch Pleasantness (TP)	Pleasant touch sensation measured using a standardized sensory brush	15 minutes

Collaborators and Investigators

• Sponsor: Aalborg University

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2021
• Primary Completion (Actual): June 30, 2021
• Study Completion (Actual): July 5, 2021

Study Registration Dates

• First Submitted: January 13, 2021
• First Submitted That Met QC Criteria: January 13, 2021
• First Posted (Actual): January 15, 2021

Study Record Updates

• Last Update Posted (Actual): July 9, 2021
• Last Update Submitted That Met QC Criteria: July 8, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Dermatologic Agents; Histamine Agents; Antipruritics; Histamine Agonists; Menthol; Histamine
• Other Study ID Numbers: N-20200005 (third sub-project)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No