Effects of High-concentration Topical Capsaicin on Histaminergic and Non-histaminergic Itch

Phase 1

Completed

• Conditions: Pruritus
• Interventions: Drug: Capsaicin 24 Hours; Drug: Capsaicin 1 Hour; Other: Qutenza Demo Patch

• Registration Number: NCT02769910
• Lead Sponsor: Hjalte Holm Andersen

Brief Summary

The purpose of this project is to investigate the effect of capsaicin-induced neurogenic inflammation with three different intensities on itch subsequently induced by histamine and cowhage. The hypothesis is that capsaicin-induced pre-established neurogenic inflammation significantly increases susceptibility to itch provocations with cowhage and histamine.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-05
• Study First Submitted: 2016-05-10
• Study First Submitted QC: 2016-05-11
• Study First Posted: 2016-05-12
• Primary Completion: 2016-07
• Study Completion: 2016-07
• Status Verified: 2016-11
• Last Update Submitted: 2016-11-19
• Last Update Posted: 2016-11-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• Healthy men and women
• 18-60 years
• Caucasian descent
• Speak and understand English

Exclusion Criteria

• Pregnancy or lactation
• Drug addiction defined as any use of cannabis, opioids or other drugs
• Previous or current neurologic, musculoskeletal or mental illnesses
• Lack of ability to cooperate
• Current use of medications that may affect the trial
• Skin diseases
• Consumption of alcohol or painkillers 24 hours before the study days and between these
• Moles or tattoos in the area to be irradiated
• Exposure of the irradiated area to UV radiation (e.g., sun) 48 hours before the study days and between these
• Acute or chronic pain
• Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical trials)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Cowhage	Capsaicin 24 Hours	Cowhage is used to induce non-histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hours and Qutenza Demo Patch.
Cowhage	Qutenza Demo Patch	Cowhage is used to induce non-histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hours and Qutenza Demo Patch.
Histamine	Capsaicin 24 Hours	Histamine is used to induce histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hour and Qutenza Demo Patch.
Histamine	Qutenza Demo Patch	Histamine is used to induce histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hour and Qutenza Demo Patch.
Cowhage	Capsaicin 1 Hour	Cowhage is used to induce non-histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hours and Qutenza Demo Patch.
Histamine	Capsaicin 1 Hour	Histamine is used to induce histaminergic itch on the volar forearm at the locations treated with Capsaicin 24 Hours, Capsaicin 1 Hour and Qutenza Demo Patch.

Primary Outcome Measures

Name	Time	Method
Itch intensity	Assessed continuously at 0-10 minutes following itch provocation	Rating of the perceived itch intensity on a visual analogue scale (VAS) App (Aalborg University) as displayed on a tablet computer with a sample rate of 1 Hz.

Secondary Outcome Measures

Name	Time	Method
Wheal size	Assessed at 10 minutes following itch provocation	Histamine wheal size is assessed by measuring the longest diameter of the wheal with a ruler, followed by measuring the orthogonal diameter. The mean of these diameters will represent the wheal size in diameter, reported in mm.
Neurogenic inflammation	Assessed 11 minutes after itch provocation	Neurogenic inflammation in the treated area is assessed using full-field laser perfusion imaging (FLPI)
Pain intensity	Assessed continuously at 0-10 minutes following itch provocation	Rating of the perceived pain intensity on a visual analogue scale (VAS) App (Aalborg University) as displayed on a tablet computer with a sample rate of 1 Hz.
Changes in sensitivity to touch-evoked itch	Assessed before, and at 12-15 minutes following itch provocation	Three von Frey filaments are applied to the test area before and after itch provocation. Subjects report three NRS scores ('0-10', 'No itch-Worst imaginable itch') for itch induced by von Frey stimulation. Change is calculated by subtracting baseline mean from post-provocation mean NRS scores.
Pain during capsaicin application	24 hours after first application of capsaicin patch	Peak and average numerical rating scale (NRS) scores ('0-10, 'no pain-worst imaginable pain') are reported by subjects for each patch.

Trial Locations

Locations (1)

SMI; 🇩🇰 Aalborg, NJ, Denmark