Itch Sensation Induced by Simultaneous Application of Pruritogens (Spatial Summation)

NCT ID: NCT06328530

Last Updated: 2024-05-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-04-01
• Study Completion Date: 2026-12-31

Brief Summary

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

Detailed Description

Chronic itch affects approximately a fifth of the global population and is associated with substantial negative consequences for the affected individuals. Furthermore, there is a lack of efficient treatment options for chronic itch. In order to mimic a clinical itch condition as presented in patients, the aim of the project is to investigate a new itch model based on the spatial summation of pruritic stimuli. The aim of this experiment is to assess the itch sensation induced by simultaneous application of pruritogens (spatial summation). In particular, the purpose is to evaluate if a single application of cowhage/histamine (non-histaminergic and histaminergic itch respectively) results in a lower itch sensation compared to two simultaneous applications of the pruritogens, on the same arm or in different arms.

Conditions

Histamine; Cowhage

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

1st pruritogen

The subproject consists of 2 sessions 3 days apart. Each session consists of 3 parts.

In the first session, 3 test areas (4x4 cm) will be selected on the subject's forearms. In part 1, we will apply cowhage in one area. In part 2, we will apply cowhage in two areas on the same arm. In part 3, we will again apply cowhage in 2 areas, one on each arm. In each part, the itch intensity will be measured using a VAS (visual analog scale) for 10 min from the cowhage application. After removal of the cowhage, alloknesis and mechanically evoked itch will be measured in the area selected in part 1.

Group Type: EXPERIMENTAL

Cowhage

Intervention Type: 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

The second session will take place 3 days after the first one and will follow the same procedure as session 1. However, histamine will be applied instead of cowhage. The order of the two sessions will be randomized.

Group Type: OTHER

Histamine

Intervention Type: 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 with 120 g of pressure for 1-2 seconds.

Interventions

Cowhage

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.

Intervention Type: OTHER

Histamine

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 with 120 g of pressure for 1-2 seconds.

Intervention Type: OTHER

Eligibility Criteria

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 (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)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Aalborg University

OTHER

Sponsor Role: lead

Responsible Party

Silvia Lo Vecchio

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Aalborg University

Aalborg, , Denmark

Site Status: RECRUITING

Countries

Denmark

Central Contacts

Silvia Lo Vecchio, PhD

Role: CONTACT

slv@hst.aau.dk

+4521397785

Giulia Erica Aliotta, PhD

Role: CONTACT

gea@hst.aau.dk

50290580

Facility Contacts

Silvia Lo Vecchio

Role: primary

slv@hst.aau.dk

+4521397785

Other Identifiers

N-20210046 3rd project

Identifier Type: -

Identifier Source: org_study_id