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A Mechanistic Evaluation of the Nociceptive Desensitizing Properties of Topical Capsaicin

Primary Purpose

Capsaicin, Ultaviolet B Light Burn, Neuropathic Pain

Status

Completed

Phase

Not Applicable

Locations

Denmark

Study Type

Interventional

Intervention

Capsaicin Topical

Ultraviolet-B (UVB) irradiation

Histamine 1%

Lidocaine

About this trial

This is an interventional basic science trial for Capsaicin

Eligibility Criteria

18 Years - 60 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion criteria:

Healthy men and women
18-60 years
Caucasian descent (only in sub-study 1)
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 treated or tested.
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)
Known history of anaphylactic shock, or local allergy (contact dermatitis) to lidocaine, prilocaine or other local anaesthetics of the amide type.

Sites / Locations

Silvia Lo Vecchio

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Arm Label

Capsaicin+UVB group

Capsaicin + EMLA group

Arm Description

All subjects will be treated with capsaicin, placebo + UVB, or Capsaicin+UVB.

All subjects will be pre-treated with lidocain cream before capsaicin application

Outcomes

Primary Outcome Measures

Superficial blood perfusion measured by a Speckle contrast imager (FLPI, Moor Instruments, England).

Measurement of Warm Detection Thresholds and Heat thresholds by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

Measurement of Pain to Supra-threshold Heat Stimuli by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

Measurement of Mechanical Pain Thresholds and Sensitivity using a pin-prick set consisting of 8 needles each having a diameter of 0.6 mm and different force applications: 0.8, 1.6, 3.2, 6.4, 12.8, 25.6, 50.1 and 60.0 g.

Trans-epidermal Water Loss (TEWL) using a 2x2 cm probe to measure the humidity gradient of the skin.

Secondary Outcome Measures

assessment of pain rating by using a visual analog scales (VAS)

The subject will report the peak and average of the perceived pain sensation during the last 24 hours (on a VAs scale from 0 indicating 'no pain' to100 indicating 'worst imaginable pain').

Itch rating by using a visual analog scales (VAS)

Itch is monitored for 9 minutes using a visual analog scale from 0 indicating 'no itch' to100 indicating 'worst imaginable itch.

Full Information

NCT ID

NCT03587220

First Posted

June 21, 2018

Last Updated

April 17, 2020

Sponsor

Aalborg University

1. Study Identification

Unique Protocol Identification Number

NCT03587220

Brief Title

A Mechanistic Evaluation of the Nociceptive Desensitizing Properties of Topical Capsaicin

Official Title

En undersøgelse af Mekanismerne Bag Nociceptiv Desensibilisering forårsaget af Topikal Capsaicin

Study Type

Interventional

2. Study Status

Record Verification Date

April 2020

Overall Recruitment Status

Completed

Study Start Date

August 1, 2018 (Actual)

Primary Completion Date

August 31, 2019 (Actual)

Study Completion Date

December 31, 2019 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Principal Investigator

Name of the Sponsor

Aalborg University

4. Oversight

Studies a U.S. FDA-regulated Drug Product

Studies a U.S. FDA-regulated Device Product

Data Monitoring Committee

5. Study Description

Brief Summary

The aim of this project is to study the role of transient receptor potential (TRP-) channel V1 (TRPV1+) fibers in the development of cutaneous inflammation induced by epidermal Ultraviolet-B damage. Moreover, in this project the investigators want to evaluate if the capsaicin-desensitization action can still be induced in a skin area pretreated with topical, local anesthetic lidocaine.

Detailed Description

In this project the Ultraviolet- B pain model, a model using type B ultraviolet rays to induce a first-degree sunburn, will be used to induce a non-specific inflammation in the skin. This model is well-known to produce both peripheral and central hyperalgesia through sensitization of peripheral and central nociceptors. Capsaicin, the active substance in chili peppers, is currently used to treat peripheral neuropathic pain, and prolonged application of 8% capsaicin patch causes profound desensitization to painful heat stimuli and itch provocations. Therefore, the investigators would like to monitor the development of unspecific UVB-cutaneous inflammation and consequent neurogenic flare in a capsaicin pre-treated area. Moreover the investigators want to test if pre-treating the skin with lidocaine can reduce the pain associated with the capsaicin application without affecting its desensitization action.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Capsaicin, Ultaviolet B Light Burn, Neuropathic Pain, Lidocaine

7. Study Design

Primary Purpose

Basic Science

Study Phase

Not Applicable

Interventional Study Model

Parallel Assignment

Masking

Participant

Allocation

Randomized

Enrollment

44 (Actual)

8. Arms, Groups, and Interventions

Arm Title

Capsaicin+UVB group

Arm Type

Experimental

Arm Description

All subjects will be treated with capsaicin, placebo + UVB, or Capsaicin+UVB.

Arm Title

Capsaicin + EMLA group

Arm Type

Experimental

Arm Description

All subjects will be pre-treated with lidocain cream before capsaicin application

Intervention Type

Drug

Intervention Name(s)

Capsaicin Topical

Intervention Description

Capsaicin patches (dosage form: patch 8% Qutenza) will be applied on 4x4 cm squared areas on the volar forearm. The patches will be left in place for 24h and 3 hours after which they will be removed.

Intervention Type

Radiation

Intervention Name(s)

Ultraviolet-B (UVB) irradiation

Intervention Description

Two circular areas (Ø 2 cm) on the forearm are irradiated with 2 x MED (Minimal Erythema Dose) dose of UVB using a calibrated UVB machine (290-320nm wavelength), Saal Mann Multi Tester (Mann Saal, LT SBC 400 Herford, Germany).

Intervention Type

Other

Intervention Name(s)

Histamine 1%

Intervention Description

To deliver histamine, standard allergy skin prick test (SPT) lancets are applied. The lancets have a 1 mm shouldered tip adapt to introduce a small amount of test substance extremely locally and approximately at the dermo-epidermal junction.

Intervention Type

Drug

Intervention Name(s)

Lidocaine

Intervention Description

Cutaneous anaesthesia will be topically induced by using EMLA cream 5%, a local anaesthetic cream consisting of equal parts of lidocaine and prilocaine (1g contains 25 mg of lidocaine and 25 mg of prilocaine)

Primary Outcome Measure Information:

Title

Superficial blood perfusion measured by a Speckle contrast imager (FLPI, Moor Instruments, England).

Time Frame

Changes from baseline to 7 days after intervention

Title

Measurement of Warm Detection Thresholds and Heat thresholds by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

Time Frame

Changes from baseline to 7 days after intervention

Title

Measurement of Pain to Supra-threshold Heat Stimuli by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

Time Frame

Changes from baseline to 7 days after intervention

Title

Time Frame

Changes from baseline to 7 days after intervention

Title

Trans-epidermal Water Loss (TEWL) using a 2x2 cm probe to measure the humidity gradient of the skin.

Time Frame

Changes from baseline to 7 days after intervention

Secondary Outcome Measure Information:

Title

assessment of pain rating by using a visual analog scales (VAS)

Description

The subject will report the peak and average of the perceived pain sensation during the last 24 hours (on a VAs scale from 0 indicating 'no pain' to100 indicating 'worst imaginable pain').

Time Frame

Change from baseline to 24 h

Title

Itch rating by using a visual analog scales (VAS)

Description

Itch is monitored for 9 minutes using a visual analog scale from 0 indicating 'no itch' to100 indicating 'worst imaginable itch.

Time Frame

Changes from baseline to 7 days after intervention

10. Eligibility

Sex

All

Minimum Age & Unit of Time

18 Years

Maximum Age & Unit of Time

60 Years

Accepts Healthy Volunteers

Eligibility Criteria

Inclusion criteria: Healthy men and women 18-60 years Caucasian descent (only in sub-study 1) 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 treated or tested. 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) Known history of anaphylactic shock, or local allergy (contact dermatitis) to lidocaine, prilocaine or other local anaesthetics of the amide type.

Facility Information:

Facility Name

Silvia Lo Vecchio

City

Aalborg

State/Province

Nordjylland

ZIP/Postal Code

9000

Country

Denmark

12. IPD Sharing Statement

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A Mechanistic Evaluation of the Nociceptive Desensitizing Properties of Topical Capsaicin

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