Testing Protocol to Efficiently Induce Itch

NCT05195177 | Unknown DMC

• 1 other identifier: N-2020001 4-sub-project
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This subproject aims to evaluate a new nerve excitability protocol to induce itch in healthy controls by electrical stimulation. Itch has many similarities with pain, and the nerve fibers that mediate the two sensations probably have the same morphological and excitability properties. The method used in this project will be the same as our research group uses for studying nociceptor fibers (PTT technique), but the focus is on the itch sensation. Since the itch fibers also terminate in the epidermis, our PTT technique should also be able to activate itch fibers, similar to pain fibers. If itch could be effectively induced by electrical stimulation, this would generate a valuable tool for studying itch in healthy controls. The sub-project takes place in 2 sessions (2 hours each).

Conditions

Itch

Outcome Measures

Primary Outcomes (16)

• Perception threshold for pulse shape 1

  The perception threshold will be estimated for the electrical stimuli with pulse shape 1. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 2

  The perception threshold will be estimated for the electrical stimuli with pulse shape 2. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 3

  The perception threshold will be estimated for the electrical stimuli with pulse shape 3. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 4

  The perception threshold will be estimated for the electrical stimuli with pulse shape 4. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 1 when antihistamine cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 1 when anti-histamine cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session one. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 2 when anti-histamine cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 2 when anti-histamine cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session one. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 3 when anti-histamine cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 3 when anti-histamine cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session one. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 4 when anti-histamine cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 4 when anti-histamine cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session one. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 1 when local anaesthetic cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 1 when local anaesthetic cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 2 when local anaesthetic cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 2 when local anaesthetic cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 3 when local anaesthetic cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 3 when local anaesthetic cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session two. The outcome measure takes approximately 5 minutes to estimate.

• Perception threshold for pulse shape 4 when local anaesthetic cream has been applied

  The perception threshold will be estimated for the electrical stimuli with pulse shape 4 when local anaesthetic cream has been applied for approximately an hour. The perception threshold is defined as the transcutaneous electrical current needed for the participant to perceive the stimulus. The electrode will be placed on the arm. The perception threshold will be estimated by the method of limits and the psi method.

  This outcome measurement will be estimated during session two. The outcome measure takes approximately 5 minutes to estimate.

• Sensation for pulse 1

  The investigator will ask the participant to rate the sensation of electrical stimulation with pulse 1 for the three different conditions. The conditions are: control (not active cream), antihistamine cream, and local anesthetic cream. The scale is 0-10 for the three sensations touch, itch, and pain. Zero means no sensation, and ten is the worst pain/touch/itch imaginable.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Sensation for pulse 2

  The investigator will ask the participant to rate the sensation of electrical stimulation with pulse 2 for the three different conditions. The conditions are: control (not active cream), antihistamine cream, and local anesthetic cream. The scale is 0-10 for the three sensations touch, itch, and pain. Zero means no sensation, and ten is the worst pain/touch/itch imaginable.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Sensation for pulse 3

  The investigator will ask the participant to rate the sensation of electrical stimulation with pulse 3 for the three different conditions. The conditions are: control (not active cream), antihistamine cream, and local anesthetic cream. The scale is 0-10 for the three sensations touch, itch, and pain. Zero means no sensation, and ten is the worst pain/touch/itch imaginable.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

• Sensation for pulse 4

  The investigator will ask the participant to rate the sensation of electrical stimulation with pulse 4 for the three different conditions. The conditions are: control (not active cream), antihistamine cream, and local anesthetic cream. The scale is 0-10 for the three sensations touch, itch, and pain. Zero means no sensation, and ten is the worst pain/touch/itch imaginable.

  This outcome measurement will be estimated during sessions one and two. The outcome measure takes approximately 5 minutes to estimate.

Study Arms (1)

Study group

EXPERIMENTAL

Drug: Anti-histamine cream 1 hour; Drug: Local anesthetic cream 1 hour

Interventions

Anti-histamine cream 1 hour DRUG

At the start of session 1, one area of the middle forearms of the participant will be located (4x4cm). On the area, anti-histamine cream will be applied for approximately 1 hour.

Study group

Local anesthetic cream 1 hour DRUG

At the start of session 2, one area of the middle forearms of the participant will be located (4x4cm). On the area, local anesthetic cream (2.5% lidocain/2.5 prilocaine) will be applied for approximately 1 hour.

Study group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy men and women in the age 18-80 years who speak and understand

You may not qualify if:

• Pregnancy or breast feeding
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Previous and present neurologic, musculoskeletal or mental illnesses (e.g., epilepsy, neuropathy, fibromyalgia and depression)
• Skin diseases
• Past history of conditions possibly leading to neuropathy
• Inability to cooperate
• Current use of medications that may affect the study, e.g., analgesics
• Previous traumatic experience of an electrical accident
• Consumption of alcohol or painkillers within the last 24 hours
• Participation in other pain studies throughout the study period
• Patients with cardiac diseases (e.g., pacemaker).

Sponsors & Collaborators

• Aalborg University: lead

Study Sites (1)

Aalborg University

Aalborg, Aalborg Ø, 9220, Denmark

Location

MeSH Terms

Conditions

Pruritus

Condition Hierarchy (Ancestors)

Skin Diseases; Skin and Connective Tissue Diseases; Skin Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Jenny Tigerholm

  Aalborg University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: November 23, 2021
• First Posted: January 18, 2022
• Study Start: November 25, 2021
• Primary Completion: December 20, 2023
• Study Completion: December 20, 2023
• Last Updated: August 2, 2023

Record last verified: 2023-08

Locations

DK (1)