Inhibition of Non-histaminergic Pruritus Applied Using 3 Different Pruritogens

Not Applicable

Completed

• Conditions: Itch
• Interventions: Drug: Emla 1 hour; Drug: EMLA 3 hours; Other: Vehicle cream for 1 hour; Other: Vehicle cream for 3 hours; Other: Cowhage

• Registration Number: NCT04858360
• Lead Sponsor: Aalborg University

Brief Summary

With this experiment, we want to use to investigate whether repeated application of EMLA cream as a tool to modulate non-histaminergic itching, which is produced using small needles from the plant mucuna pruriens (it is known that antihistamine does not attenuate this form of itch) and we want to compare the effect of short (1 hour) and prolonged (3 hours) application of EMLA. The sub-project takes place in 3 sessions over a period of 3 consecutive days (24 hours apart). All sessions will be identical.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-04-21
• Study First Submitted QC: 2021-04-21
• Study First Posted: 2021-04-26
• Study Start: 2021-11-15
• Primary Completion: 2022-08-01
• Study Completion: 2022-10-01
• Status Verified: 2023-01
• Last Update Submitted: 2023-01-16
• Last Update Posted: 2023-01-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 22

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 that may affect the results (e.g. neuropathy, muscular pain in the upper extremities, etc.).
• Lack of ability to cooperate
• Current use of medications that may affect the trial such as antihistamine medications or pain killers.
• Skin diseases
• Hypersensitivity to papaya and mango fruit, cashew nuts and rubber latex
• 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
Study group	Emla 1 hour	-
Study group	EMLA 3 hours	-
Study group	Vehicle cream for 1 hour	-
Study group	Vehicle cream for 3 hours	-
Study group	Cowhage	-

Primary Outcome Measures

Name	Time	Method
Measuring Hyperknesis	10 min after cowhage application	Hyperknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).
Measuring itch intensity by computerized Visual Analog Scale Scoring	For 9 minutes	We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable
Measuring pain intensity by computerized Visual Analog Scale Scoring	For 9 minutes	We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".
Superficial blood perfusion measurement	10 min after cowhage application	Superficial blood perfusion is measured by a Speckle contrast imager
Measuring Alloknesis	10 min after cowhage application	Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.

Secondary Outcome Measures

Name	Time	Method
Measuring Erythema	10 min after cowhage application	The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).
Measuring Skin Pigmentation	10 min after cowhage application	The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

Trial Locations

Locations (1)

Aalborg University; 🇩🇰 Aalborg, Denmark