Off-set Analgesia Induced by Cold Temperature

Pain and Itch Neuromodulation: Effects of Offset Analgesia, Placebo, and Nocebo and Topographical Distribution of Itch and Pain Receptors

In this study, it will be investigated if the phenomenon of offset analgesia, usually associated with painful heat stimulation, could also be induced using cold painful temperatures.

After filling some questionnaires, two areas (4x4 cm, 4 cm apart) will be selected on each forearm of the subjects. The areas will be randomly treated with one of the following trials: hot experimental trial, hot control trial, cold experimental trial, and cold control trial.

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, immunological, musculoskeletal, cardiac disorder or psychiatric diagnoses that may affect the results (e.g., neuropathy, muscular pain in the upper extremities, anxiety, depression, schizophrenia, etc.)
• Moles, wounds, scars, or tattoos in the area to be treated or tested
• 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 and itch
• Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical studies)
• Contraindications to capsaicin, including intolerance to chili or burns or wounds at the application site (sub-project 4 only)
• The subject is assessed as unable to engage in the necessary cooperation required by the study