Topographical Distribution of Itch and Pain Receptors

Launched by AALBORG UNIVERSITY · Aug 13, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how itch and pain sensations are distributed on the face and how different substances affect these feelings. The researchers want to learn more about how the skin reacts to things that cause itching or pain by testing specific areas on your face over three days. During the study, participants will answer questions about how they experience itch and pain, as well as some questions about mood and stress. The team will also measure skin responses like blood flow and sensitivity to touch, pressure, and light pinpricks. Different substances—histamine, cowhage (a plant that causes itch), and capsaicin (the spicy component in chili peppers)—will be applied to the face to see how these affect the sensations compared to inactive patches.

To take part, you need to be a healthy adult between 18 and 60 years old who speaks and understands English. People who are pregnant, have certain health conditions, skin problems, or use certain medications won’t be able to join. If you participate, the study will involve three visits on consecutive days, each lasting a few hours. You can expect gentle tests on your face and applications of mild substances that may cause temporary itch or burning sensations. It’s important that you avoid alcohol, painkillers, and some other substances before and during the study. This trial is not yet recruiting, but it offers a chance to help researchers better understand how our skin senses itch and pain, which could lead to improved treatments in the future.

Gender

ALL

Eligibility 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