Inhibition of Non-histaminergic Pruritus Applied Using 3 Different Pruritogens

Itch Clinical Trial

Official title:

Evaluation of the Effect of Repeated Administration of Topical Local Anaesthetic Mixture of Lidocaine and Prilocaine (EMLA) in a Model of Non-histaminergic Itch Induced by Cowhage.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04858360
• Other study ID #: N-20200073 1st sub-project
• Status: Completed
• Phase: N/A
• Start date: November 15, 2021
• Est. completion date: October 1, 2022

Study information

• Verified date: January 2023
• Source: Aalborg University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 22
• Est. completion date: October 1, 2022
• Est. primary completion date: August 1, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

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.

Related Conditions & MeSH terms

• Itch

Intervention

Drug:
• Emla 1 hour
At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then one area will be pre-treated with cutaneous 2.5% lidocaine/2.5% prilocaine cream (EMLA cream) for 1 hour.
• EMLA 3 hours
At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then one area will be pre-treated with cutaneous 2.5% lidocaine/2.5% prilocaine cream (EMLA cream) for 3 hours.

Other:
• Vehicle cream for 1 hour
At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then two area will be pre-treated with a vehicle cream for 1 h.
• Vehicle cream for 3 hours
At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then two area will be pre-treated with a vehicle cream for 3 h.
• Cowhage
Cowhage spicules are 1-2 mm in length and have a diameter of 1-3 µm. The spicules are inserted by gently rubbing 30-35 spicules into a 1 cm diameter skin area.

Locations

Country	Name	City	State
Denmark	Aalborg University	Aalborg

Sponsors (1)

Lead Sponsor	Collaborator
Aalborg University

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Measuring itch intensity by computerized Visual Analog Scale Scoring	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	For 9 minutes
Primary	Measuring pain intensity by computerized Visual Analog Scale Scoring	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".	For 9 minutes
Primary	Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	After 1 hour
Primary	Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	After 3 hours
Primary	Superficial blood perfusion measurement	Superficial blood perfusion is measured by a Speckle contrast imager	10 min after cowhage application
Primary	Measuring Alloknesis	Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.	After 1 hour
Primary	Measuring Alloknesis	Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.	After 3 hours
Primary	Measuring Alloknesis	Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.	10 min after cowhage application
Primary	Measuring Hyperknesis	Hyperknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).	After 1 hour
Primary	Measuring Hyperknesis	Hyperknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).	After 3 hours
Primary	Measuring Hyperknesis	Hyperknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).	10 min after cowhage application
Secondary	Measuring Erythema	The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	After 1 hour
Secondary	Measuring Erythema	The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	After 3 hours
Secondary	Measuring Erythema	The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	10 min after cowhage application
Secondary	Measuring Skin Pigmentation	The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	After 1 hour
Secondary	Measuring Skin Pigmentation	The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	After 3 hours
Secondary	Measuring Skin Pigmentation	The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).	10 min after cowhage application