NCT04515056

Characterization of New Human Models of Non-histaminergic Itch

Characterization of New Human Models of Non-histaminergic Itch and Their Interaction With the TRPM8 Receptor

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (actual)
• Sponsor: Aalborg University · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

In this experiment the investigators would like to test a new new human itch model based on papain, and to characterize the sensory quality and temporary aspects of papain skin prick test (SPT) in comparison to the inactivated-cowhage delivery system.

Detailed description

The most used model of non-histaminergic itch is cowhage but this models presents several problems, such us the impossibility of standardizing the amount of the spicules inserted in the skin and the difficulty of obtaining the substance. These aspects bring us the necessity to find a new and more standardized model of non-histaminergic itch. Papain is a cysteine protease extracted from papaya plant that is known to cause itch if applied to the skin. For these reasons the investigators would like to test a new new human itch model based on papain, and to characterize the sensory quality and temporary aspects of papain skin prick test (SPT) in comparison to the inactivated-cowhage delivery system.

Conditions

• Papain
• Itch
• Skin Prick Test (SPT)

Interventions

Type	Name	Description
DRUG	Papain 10 µg	The area will be exposed to 10 µg of papain.
DRUG	Papain 50 µg	The area will be exposed to 50 µg of papain.
DRUG	Papain 100 µg	The area will be exposed to 100 µg of papain.
OTHER	Vehicle	The area will be exposed to vehicle
DRUG	Papain 1 SPT	Papain will be applied by 1 SPT prick thought the skin
DRUG	Papain 5 SPT	Papain will be applied by 5 SPT pricks thought the skin
DRUG	Papain 25 SPT	Papain will be applied by 25 SPT pricks thought the skin
OTHER	Cowhage	The last area will be exposed to cowage spicules (made chemically inert by autoclaving) soaked in 5 mg/ml papain solution.

Timeline

• Start date: 2020-09-01
• Primary completion: 2021-06-01
• Completion: 2021-06-01
• First posted: 2020-08-17
• Last updated: 2021-07-09

Locations

1 site across 1 country: Denmark