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 antagonist (A-967079)
Interventions
A-967079 solution (in PBS 0.5 mg/ml, subcutaneous injection of 0.1ml) 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
A-967079 solution (in PBS 0.5 mg/ml, subcutaneous injection of 0.1ml). BAM8-22 with inactivate cowhage spicules 20 µl of BAM8-22 will be applied 5 minutes after to a previously determined area on the volar forearm using inactivate cowhage spicules
A-967079 solution (in PBS 0.5 mg/ml, subcutaneous injection of 0.1ml) will be applied to a previously determined area on the volar forearm
Vehicle (in PBS, subcutaneous injection of 0.1ml) 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
Sponsors
Study design
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 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 |
| Warm Detection Threshold, and Heat Pain threshold | change from baseline, up to 10 minutes after the application | he tests for thermal sensation will all be performed using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device |
| superficial blood perfusion | change from baseline, up to 10 minutes after the application | is measured by a speckle contrast imager (FLPI, Moor Instruments, England) |
| Cold Detection Threshold and 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 |
| Alloknesis | change from baseline, up to 10 minutes after the application | s measured by using a mildy pruritic, non-painful von Frey filaments of a predetermined intensity (generally 5-30 milliNewton of force) |
| mechanical pain threshold and 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