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

NCT ID: NCT06328543

Last Updated: 2024-11-22

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 26 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-11-01
• Study Completion Date: 2026-12-31

Brief Summary

In This experiment, the investigators would like to design a new itch model based on the 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.

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 multiple applications of pruritogens (temporal 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 with two overlapped applications of the pruritogens on the same area.

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 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.

Group Type: EXPERIMENTAL

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.

2nd pruritogen

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.

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.

Interventions

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.

Intervention Type: OTHER

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

Eligibility Criteria

Inclusion Criteria

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

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, 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, PhD

Role: primary

slv@hst.aau.dk

0045+21397785

Silvia Lo Vecchio, PhD

Role: backup

Other Identifiers

N-20210046 4th project

Identifier Type: -

Identifier Source: org_study_id