Itch
Conditions
Brief summary
With this experiment, the experimenter wish evaluate the role of TRPA1 on non-histaminergic itch induced by BAM8-22
Detailed description
With this experiment, the experimenter wish evaluate the role of TRPA1 on non-histaminergic itch induced by BAM8-22 2 (Bovine Adrenal Medulla), which is found naturally in the human body and which has proved to evoke itch. To evaluate the role of TRPA1 it will be used a TRPA1 agonist
Interventions
DRUGCA and BAM8-22
CA (tran-cinnamaldheyde) solution (in ethanol 5%) application and BAM8-22 with inactivate cowhage spicules 20 µl of BAM8-22 will be applied to a previously determined area on the volar forearm using inactivate cowhage spicules
DRUGVehicle and BAM8-22 application
Vehicle (ethanol) application and BAM8-22 with inactivate cowhage spicules 20 µl of BAM8-22 will be applied to a previously determined area on the volar forearm using inactivate cowhage spicules
DRUGCA
CA (tran-cinnamaldheyde) solution (in ethanol 5%) application to a previously determined area on the volar forearm
DRUGvehicle
Vehicle (ethanol) application and inactivate cowhage spicules will be applied to a previously determined area on the volar forearm
Sponsors
Aalborg University
Study design
Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
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 history of neurological, dermatological, immunological musculoskeletal, cardiac disorder or mental illnesses that may affect the results (e.g. neuropathy, muscular pain in the upper extremities, etc.) * Moles, wounds, scars or tattoos in the area to be treated or tested * Lack of ability to cooperate • * Current use of medications that may affect the trial such as antihistamines and pain killers. * 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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| itch rating | change from baseline, up to 10 minutes after the application | the subject will rate the itch for 10 minutes by using a visual analog scale (VAS) on a tablet. this scale goes from 0 to 100. 0 indicates no itch and 100 indicates worst imaginable itch |
| superficial blood perfusion | change from baseline, up to 10 minutes after the application | is measured by a speckle contrast imager (FLPI, Moor Instruments, England) |
| Warm Detection Threshold | change from baseline, up to 10 minutes after the application | the tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| Heat Pain threshold | change from baseline, up to 10 minutes after the application | the tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| Cold Detection Threshold | change from baseline, up to 10 minutes after the application | the tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| Cold Pain threshold | change from baseline, up to 10 minutes after the application | the tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| Pain supra-threshold heat Stimuli | change from baseline, up to 10 minutes after the application | the tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| hyperknesis | change from baseline, up to 10 minutes after the application | measured by using a mildy pruritic, non-painful von Frey filaments of a predetermined intensity (5-30 milliNewton of force). participants will rate the itch sensation induced by stimuli with von Frey filaments on an numerical rating scale from 0 to 10 |
| mechanical pain threshold | change from baseline, up to 10 minutes after the application | is performed using a pin-prick set (Aalborg University). The set consists of 8 needles each having a diameter of 0,6 mm and different force applications. it will be determinate a threshold corresponding to the force of the pinprick (mN) from which participants start to feel pain |
| mechanical pain sensitivity | change from baseline, up to 10 minutes after the application | is performed using a pin-prick set (Aalborg University). The set consists of 8 needles each having a diameter of 0,6 mm and different force applications |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| pain rating | change from baseline, up to 10 minutes after the application | the subject will rate the pain for 10 minutes by using 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 |
Countries
Denmark
Outcome results
None listed