Repetitive Applications of Pruritogens and Effects of a Cutaneous-induced Pain Stimulation on Nonhistaminergic Itch Perception

NCT06185582 | Unknown DMC

• 1 other identifier: N-20210046 2nd project
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

In This experiment, the investigators would like to test following hypotheses: the pain stimulation applied at the same time of a pruriceptive stimulus will decrease the itch perception. Moreover, also the effect of the cutaneous pain stimulus location (same forearm of the pruriceptive stimulus versus the opposite forearm) on histaminergic and non-histaminergic itch will be investigated.

Conditions

Pain, Burning; Capsaicin

Outcome Measures

Primary Outcomes (3)

• Assessment of itch intensity using a VAS scale

  Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.

  1 minute post itch provocation

• Assessment of pain intensity using a VAS scale

  Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.

  1 minute post itch provocation

• Retrospective rating of the pain perceived on a NRS

  After 10 minutes of pruritogens application, a retrospective rating of the pain perceived from the thermal pain/capsaicin will be provided by the subject using a numeral rating scale (NRS)

  10 minutes post itch provocation

Secondary Outcomes (2)

• Alloknesis

  12 minutes post itch provocation

• Mechanically evoked itch

  15 minutes post itch provocation

Study Arms (2)

Pain

EXPERIMENTAL

A thermode stimulator of 3x3 cm will be placed on the areas and kept in place by means of Velcro tape. The temperature raises 1°C per second from a starting temperature of 32°C until itch reach or 46.5 °C. This temperature will be maintained for 2 minutes. Then the temperature will return to baseline temperature at a rate of 5°C /s.

Other: Cowhage

Capsaicin

EXPERIMENTAL

Capsaicin patches (dosage form: transdermal patch 8% Qutenza, Astellas) will be applied on one squared area (4x4 cm2). The patch will be left in place for 20 minutes after which it will be removed.

Other: Cowhage

Interventions

Cowhage OTHER

25 spicules will be inserted in the center of the predefined skin area on the mandibular area. The spicules will be gently rubbed for 15-20 seconds in circular motion to facilitate epidermal penetration.

Capsaicin; Pain

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy men and women
• years
• Speak and understand English

You may not qualify if:

• Pregnancy or lactation
• Drug addiction defined as any use of cannabis, opioids, or other addictive drugs
• Previous or current history of neurological (e.g. neuropathy), immunological (e.g. asthma, immune deficiencies, arthritis) musculoskeletal (e.g. muscular pain in the upper extremities,), cardiac disorder, or mental illnesses that may affect the results
• 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 (e.g. atopic dermatitis, pruritus nodularis, eczema, psoriasis)
• Moles, scars, or tattoos in the area to be treated or tested.
• Consumption of alcohol or painkillers 24 hours before the study days and between these
• Acute or chronic pain
• Participation in other trials within one week of study entry (four weeks in the case of pharmaceutical trials)

Sponsors & Collaborators

• Aalborg University: lead

Study Sites (1)

Aalborg University

Aalborg, 9220, Denmark

RECRUITING

MeSH Terms

Conditions

Pain

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participant will be blinded about application of pruritogens.
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: The sub-project takes place over three sessions on three consecutive days. The participants will randomly receive two pruritogens and two pain stimulations (heat or capsaicin) in the same and in the opposite arm.

Study Record Dates

• First Submitted: November 20, 2023
• First Posted: December 29, 2023
• Study Start: December 15, 2023
• Primary Completion: December 31, 2024
• Study Completion: June 30, 2025
• Last Updated: December 29, 2023

Record last verified: 2023-12

Locations

DK (1)