Placebo effects on histamine and cowhage-induced itch
Pain and Itch Neuromodulation: Effects of Offset Analgesia, Placebo, and Nocebo and Topographical Distribution of Itch and Pain Receptors
NA · Aalborg University · NCT07247695
This one-time, 1½-hour session will test whether applying a harmless cream reduces histamine- and cowhage-induced itch in healthy adults aged 18–60.
Quick facts
| Phase | NA |
|---|---|
| Study type | Interventional |
| Enrollment | 30 (estimated) |
| Ages | 18 Years to 60 Years |
| Sex | All |
| Sponsor | Aalborg University (other) |
| Locations | 1 site (Gistrup) |
| Trial ID | NCT07247695 on ClinicalTrials.gov |
What this trial studies
Participants first complete questionnaires about how they perceive itch, pain, and mood and about personality traits. Four sites (two on each forearm) are treated with the same inert vehicle cream for 20 minutes to create a placebo context; afterward two sites are randomly challenged with histamine and two with cowhage. Itch and pain are continuously recorded on a visual analog scale during the 10-minute pruritogen application. The within-subject design in healthy volunteers compares placebo responsiveness between histaminergic and non-histaminergic itch over a single 90-minute session.
Who should consider this trial
Good fit: Healthy English-speaking adults aged 18–60 with intact forearm skin, no chronic itch or pain, not pregnant or lactating, and not taking antihistamines or painkillers are ideal candidates.
Not a fit: People with chronic or active skin disease, current use of antihistamines or pain medications, pregnancy or lactation, neurological or psychiatric disorders, recent drug use, or forearm wounds/tattoos are unlikely to be eligible or to benefit.
Why it matters
Potential benefit: If successful, the results could help develop non-drug approaches to reduce acute itch and guide use of placebo mechanisms in symptom management.
How similar studies have performed: Placebo effects on itch—especially histamine-induced itch—have been reported, but direct comparison of placebo responses between histaminergic and cowhage (non-histaminergic) itch is relatively novel.
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 University — Gistrup, Denmark (RECRUITING)
Study contacts
- Principal investigator: Silvia Lo Vecchio — Aalborg Universitet
- 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.
Conditions: ITCH