Mapping itch and pain receptor locations on the face
Pain and Itch Neuromodulation: Effects of Offset Analgesia, Placebo, and Nocebo and Topographical Distribution of Itch and Pain Receptors
We will test how itch and pain are felt at different spots on the face in healthy adults by applying mild provocations (histamine, cowhage, capsaicin) and measuring responses over three days.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 30 (estimated) |
| Ages | 18 Years to 60 Years |
| Sex | All |
| Sponsor | Aalborg University Academic / other |
| Locations | 1 site (Gistrup, Aalborg) |
| Trial ID | NCT07122973 on ClinicalTrials.gov |
What this trial studies
Participants attend three consecutive experimental sessions during which questionnaires about itch, pain, and mood are completed. In session one, six test areas on the face (jaw, cheek, temple on each side) are marked and baseline measures are taken including skin blood flow and sensitivity to pressure, pinprick, and brush. In session two, histamine is applied to one side of the face and cowhage spicules to the other, and sensory and blood-flow tests are repeated after 10 minutes. In session three, a capsaicin patch is applied to one side and a placebo patch to the other, with the same post-application testing performed.
Who should consider this trial
Good fit: Healthy adults aged 18–60 who speak English, are not pregnant or breastfeeding, have no acute or chronic itch or pain, no relevant skin disease or wounds at the test sites, and are not taking antihistamines or pain medications are ideal candidates.
Not a fit: People with chronic pain or itch conditions, active skin disease, recent use of relevant medications, pregnancy or lactation, drug use, or neurological/psychiatric disorders are unlikely to benefit and may be excluded.
Why it matters
Potential benefit: If successful, this work could improve understanding of where and how itch and pain receptors are distributed on the face, which may guide better-targeted treatments or diagnostics.
How similar studies have performed: Similar sensory research using histamine, cowhage, and capsaicin has been used successfully to provoke and characterize itch and pain responses, although detailed facial mapping is less common.
Eligibility criteria
Show full inclusion / exclusion criteria
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 * The subject is assessed as unable to engage in the necessary cooperation required by the study
Where this trial is running
Gistrup, Aalborg
- Aalborg University — Gistrup, Aalborg, Denmark (Recruiting)
Study contacts
- Study coordinator: Silvia Lo Vecchio
- Email: slv@hst.aau.dk
- Phone: +4521397785
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.