Itch Sensation Induced by Multiple Applications of Pruritogens (temporal Summation)

NCT06328543 | Recruiting DMC

• 1 other identifier: N-20210046 4th project
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief Summary

In This experiment, the investigators would like to design a new itch model based on the temporal summation of pruritic stimuli. The hypothesis behind this study (temporal summation) is that two overlapped applications of pruritogens will result in a higher itch sensation compared with a single application.

Conditions

Histamine; Cowhage

Outcome Measures

Primary Outcomes (2)

• Assessment of itch

  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 after every itch inductions

• Assessment of pain

  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 after every itch inductions

Secondary Outcomes (3)

• Microvascular reactivity

  10 minutes after every itch inductions

• Alloknesis

  12 minutes after every itch inductions

• Mechanically evoked itch

  15 minutes after every itch inductions

Study Arms (2)

1st pruritogen

EXPERIMENTAL

The subproject is conducted in 1 session (approx. 3 hours in total) divided into two parts. In the first part, 3 test areas (3x3 cm) will be selected on one forearm of the subject. The 3 areas will be randomly treated with 1 application of cowhage, 2 applications of cowhage (the second application will be conducted 90 seconds after the first one in the same area), and 2 applications of cowhage (the second application will be conducted 180 seconds after the first one in the same area). Itch will be monitored using a VAS (visual analog scale) for 15 min in each session. After the removal of cowhage, FLPI, alloknesis, and mechanically evoked itch will be measured.

Other: Histamine

2nd pruritogen

EXPERIMENTAL

The second part will be conducted 20 minutes after the first part, and the procedure will be the same, but using histamine instead of cowhage. The two parts will be randomized between subjects.

Other: Cowhage

Interventions

Histamine OTHER

Histaminergic itch will be evoked by a 1% histamine solution. A droplet of histamine solution will be placed on the predetermined area on the forearm, and the SPT lancet will be pierced through the histamine.

1st pruritogen

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.

2nd pruritogen

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 Englis

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, Aalborg, 9260, Denmark

RECRUITING

MeSH Terms

Interventions

Histamine

Intervention Hierarchy (Ancestors)

Biogenic Monoamines; Biogenic Amines; Amines; Organic Chemicals; Ethylamines; Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Autacoids; Inflammation Mediators; Biological Factors

Central Study Contacts

Silvia Lo Vecchio, PhD

CONTACT

+4521397785; slv@hst.aau.dk

Giulia Erica Aliotta, PhD

CONTACT

50290580; gea@hst.aau.dk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: 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: Associate Professor

Model Details: The participants will randomly receive applications of cowhage and histamine

Study Record Dates

• First Submitted: March 19, 2024
• First Posted: March 25, 2024
• Study Start: November 1, 2024
• Primary Completion: December 31, 2025
• Study Completion (Estimated): December 31, 2026
• Last Updated: November 22, 2024

Record last verified: 2024-11

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)