Evaluation of the Effect Induced by Repeated Administration of Topical Local Anaesthetic (EMLA) on Itch

Not Applicable

Completed

• Conditions: Itch; Lidocaine
• Interventions: Drug: EMLA (lidocaine) +Itch (Histamine and cowhage)

• Registration Number: NCT04076865
• Lead Sponsor: Aalborg University

Brief Summary

In this experiment, the investigators would like to study if the repeated application of local cuaneous anaesthetic EMLA cream will reduce itch induced by small needles from the plant mucuna pruriens (also known as cowhage) and histamine (an itch proving substance formed in the body).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2019-08-30
• Study First Submitted QC: 2019-08-30
• Study First Posted: 2019-09-03
• Study Start: 2019-10-15
• Primary Completion: 2020-10-01
• Status Verified: 2021-01
• Study Completion: 2021-01-01
• Last Update Submitted: 2021-01-13
• Last Update Posted: 2021-01-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

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 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
• 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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
EMLA	EMLA (lidocaine) +Itch (Histamine and cowhage)	-

Primary Outcome Measures

Name	Time	Method
Superficial blood perfusion	Change from baseline, up to three days after the first session	is measured by a Speckle contrast imager (FLPI, Moor Instruments, England).
Warm Detection Thresholds and Heat Pain Thresholds	Change from baseline, up to three days after the first session	The tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device
Pain rating	only on day 3 (third session)	The subject will rate the pain for 9 min by using a a visual analog scale (VAS) on a tablet. This scale goes from 0 to 100. 0 indicates 'no pain' and 100 indicates 'worst imaginable pain'.
Pain to Supra-threshold Heat Stimuli	Change from baseline, up to three days after the first session	The tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device
Alloknesis	Change from baseline, up to three days after the first session	Alloknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).
Mechanical Pain Thresholds and Sensitivity	Change from baseline, up to three days after the first session	This test is performed using a pin-prick set (Aalborg University, Aalborg). The set consists 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

Secondary Outcome Measures

Name	Time	Method
Itch rating	only on day 3 (third session)	The subject will rate the itch for 9 min by using a a visual analog scale (VAS) on a tablet. This scale goes from 0 to 100. 0 indicates 'no itch' and 100 indicated 'worst imaginable itch'.

Trial Locations

Locations (1)

Aalborg University; 🇩🇰 Aalborg, Nordjylland, Denmark