Cowhage, Histamine, Itch, Serotonine, Thermal Stimulation
Conditions
Brief summary
The purpose of this human experimental study is to evaluate the pattern of itch intensity over time in response to strong, short-term heat stimulation in two different models of histamine and cowhage-induced itch. Moreover, the purpose is to evaluate the effect of mild pre-heating of the skin in human experimental models of histamine, cowhage and serotonin. Finally, we want to investigate the effect of short-term intense heat stimulation on previously anesthetized skin.
Interventions
DRUGLidocaine
Lidocaine intradermal injection
OTHERHistamine
Skin Prick Test with Histamine
OTHERCowhage
Manually skin insertion of cowhage spicules
OTHERHeat stimulation
Short heat stimulation
OTHERPre-heating
Mild skin pre-heating
OTHERSerotonin
Serotonin electrophoresis
Sponsors
Aalborg University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Only the third sub-study is conducted in a double-blind manner.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy men and women * Age 18-60 years * Able to speak and understand English
Exclusion criteria
* Suffering from chronic disease * Pregnancy or lactation * Prior experience of adverse effects from anaesthetic, specifically Lidocaine * Drug addiction defined as the use of cannabis, opioids or other drugs - 5 - * Previous neurologic, musculoskeletal or mental illnesses * Lack of ability to cooperate * Current use of medications that may affect the trial * Active skin diseases * Active participation in other experiments currently ongoing or within the last 14 days * Tattoos on volar forearms that will interfere with local skin measurements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| eVAS Itch | 10 minutes | Electronic Visual Analog Scale for itch sensation. 0-100 scale, it measures the self-estimated itch the subject experience on a scale where 0 correspond to No itch and 100 Worst itch imaginable. |
| Skin temperature | 5 seconds | Infrared skin thermometer |
| eVAS Pain | 10 minutes | Electronic Visual Analog Scale for pain sensation. 0-100 scale, it measures the self-estimated pain the subject experience on a scale where 0 correspond to No pain and 100 Worst pain imaginable. |
Countries
Denmark
Outcome results
None listed