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PainNCT07122973

Topographical Distribution of Itch and Pain Receptors

A study testing Histamine, Cowhage and Capsaicin 8% Patch in people with Pain and Itch, run by Aalborg University at 1 site in Denmark.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The experiment consists of three experimental sessions conducted on three consecutive days. In all experimental sessions, the participant will fill in a series of questionnaires about how you perceive itch and pain, and about some traits of your personality, such as depression, anxiety and stress. Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Pain, Itch
What is being tested?
Histamine, Cowhage and Capsaicin 8% Patch
Could I receive a placebo?
No, everyone receives an active treatment
How many people
30 participants
Where
1 siteDenmark
Study dates
17 Sep 2025to 31 Dec 2028
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy men and women
  • 18-60 years
  • Speak and understand English

Who cannot join

  • 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
Show all 11Show fewer
  • 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

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Silvia Lo Vecchio contact

+4521397785

slv@hst.aau.dk

Denmark1 site, 1 recruiting
  • Aalborg University

    Gistrup, Aalborg, 9260

    Silvia Lo Vecchio, 21397785, slv@hst.aau.dk

    silvia.lovecchio@icloud.com

    Recruiting

Other trials in Denmark

About this study

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

The experiment consists of three experimental sessions conducted on three consecutive days.

In all experimental sessions, the participant will fill in a series of questionnaires about how you perceive itch and pain, and about some traits of your personality, such as depression, anxiety and stress.

Read more

In the first session, we will mark six test areas in your face (three on each side on jaw, cheek, and temple, respectively). Thent a series of measure-ments in each test area will be conducted:measurement of the blood flow in the skin and sensitivity tests to pressure, pinprick and stroke with a brush.

In the second session, histamine will be applied in one side of the face. On the other side, cowhage spicules will be applied. After 10 minutes, all the tests will be conducted again.

The third session will be identical to the second. However, instead of histamine and spicules, patches containing capsaicin will be applied. In the other side, we will apply patches with placebo (i.e., a non-active patch). After 20 minutes all the tests will be conducted again.

Conditions
Pain, Itch
Being tested
Histamine, Cowhage, Capsaicin 8% Patch, Demo patch
Medical subject headings
Pain, Pruritus

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • HistamineOther

    To deliver histamine, standard allergy skin prick test (SPT) lancets are applied

  • CowhageOther

    The spicules will be manually inserted. Approximately 30-35 spicules are gently rubbed into a 1 cm diameter skin area on the forearm/face

  • Capsaicin 8% PatchOther

    Capsaicin patches (dosage form: transdermal patch 8% Qutenza, Astellas) will be applied on 3 squared areas in the face.

  • Demo patchOther

    Placebo patch (demo patch, containing the same formulation as the active treatment with the exception of capsaicin) will be applied on 3 squared areas in the face.

Study groups in NCT07122973
Study groupRoleWhat they receive
Itch and painExperimentalNot described
Receives: Other: Histamine; Other: Cowhage; Other: Capsaicin 8% Patch; Other: Demo patch

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Measuring pain by computerized Visual Analog Scale Scoring

    We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".

    Measured: Baseline

  2. Measuring itch by computerized Visual Analog Scale Scoring

    We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable".

    Measured: Baseline

  3. Measuring pain by computerized Visual Analog Scale Scoring

    We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".

    Measured: Immediately after the intervention

  4. Measuring itch by computerized Visual Analog Scale Scoring

    We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable".

    Measured: Immediately after the intervention

Secondary outcomes (30)
  1. Superficial blood perfusion

    Superficial blood perfusion (SBP) is measured by a Speckle contrast imager

    Measured: Baseline

  2. Superficial blood perfusion

    Superficial blood perfusion (SBP) is measured by a Speckle contrast imager

    Measured: Immediately after the intervention

  3. Alloknesis

    Measured using a standardized sensory brush exerting a force of 200 to 400 mN.

    Measured: Baseline

  4. Alloknesis

    Measured using a standardized sensory brush exerting a force of 200 to 400 mN.

    Measured: Immediately after the intervention

  5. Mechanically evoked itch (MEI)

    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).

    Measured: Baseline

  6. Mechanically evoked itch (MEI)

    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force).

    Measured: Immediately after the intervention

  7. Mechanical Pain Thresholds (MPT)

    This test is conducted using a pinprick set. The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.

    Measured: Baseline

  8. Mechanical Pain Thresholds (MPT)

    This test is conducted using a pinprick set. The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.

    Measured: Immediately after the intervention

  9. Mechanical Pain Sensitivity (MPS)

    This test is conducted with the same pinprick set used to test the MPT.

    Measured: Baseline

  10. Mechanical Pain Sensitivity (MPS)

    This test is conducted with the same pinprick set used to test the MPT.

    Measured: Immediately after the intervention

  11. Cold Detection Thresholds (CDT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Baseline

  12. Cold Detection Thresholds (CDT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Immediately after the intervention

  13. Warm Detection Thresholds (WDT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Baseline

  14. Warm Detection Thresholds (WDT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Immediately after the intervention

  15. Cold Pain Thresholds (CPT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Baseline

  16. Cold Pain Thresholds (CPT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Immediately after the intervention

  17. Heat Pain Thresholds (HPT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Baseline

  18. Heat Pain Thresholds (HPT)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Immediately after the intervention

  19. Pain to Supra-threshold Heat Stimuli (STHS)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Baseline

  20. Pain to Supra-threshold Heat Stimuli (STHS)

    The tests of thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device

    Measured: Immediately after the intervention

  21. Pain Catastrophizing Scale (PCS).

    The PCS assesses negative and exaggerated coping concerning anticipated or experienced painful stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).

    Measured: Baseline

  22. Itch Catastrophizing Scale (ICS).

    The ICS assesses negative and exaggerated coping concerning anticipated or experienced itchy stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).

    Measured: Baseline

  23. Learned Helplessness Scale (LHS)

    The questionnaire consists of 20 items, and the participant's response to each item is rated on a 4-point Likert scale ranging from strongly agree (1) to strongly disagree (4).

    Measured: Baseline

  24. Learned Helplessness Scale (LHS)

    The questionnaire consists of 20 items, and the participant's response to each item is rated on a 4-point Likert scale ranging from strongly agree (1) to strongly disagree (4).

    Measured: 10 minutes after every induction

  25. Pain Catastrophizing Scale (PCS).

    The PCS assesses negative and exaggerated coping concerning anticipated or experienced painful stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).

    Measured: 10 minutes after induction

  26. Itch Catastrophizing Scale (ICS).

    The ICS assesses negative and exaggerated coping concerning anticipated or experienced itchy stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).

    Measured: 10 minutes after induction

  27. Depression, Anxiety, Stress Scale (DASS-21)

    The questionnaire measures the magnitude of depression, anxiety, and stress. Each of these three subscales consists of 7 questions answered using a 0-3 Likert scale, with 0 meaning "it did not apply to me", and 3 meaning "it applied to me very much"

    Measured: Baseline

  28. Reinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ).

    The RST-PQ contains in total, 65 items must be answered on a 4-point Likert-type scale

    Measured: Baseline

  29. Difficulties in Emotion Regulation Scale Short Form (DERS-SF)

    The questionnaire is an 18-item measure used to identify emotional regulation issues in adults. Participants rate each item on a 5-point Likert scale (from 1 to 5).

    Measured: Baseline

  30. Emotion Regulation Questionnaire (ERQ

    This questionnaire is designed to assess individual differences in the habitual use of two emotion regulation strategies: cognitive reappraisal and expressive suppression. Respondents answer each item on a 7-point Likert-type scale ranging from 1 (strongly disagree) to 7 (strongly agree), where 4 means (neutral).

    Measured: Baseline

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Aug 2025
  2. Study start17 Sep 2025
  3. Primary completion31 Dec 2026 (estimated)
  4. Study completion31 Dec 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
30 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07122973
Sponsor's protocol ID
N-20250017 Project 4
Status last verified
Nov 2026
First submitted
13 Aug 2025
Last updated
6 Nov 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Histamine, Cowhage and Capsaicin 8% Patch in people with Pain and Itch, run by Aalborg University at 1 site in Denmark.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Silvia Lo Vecchio (+4521397785, slv@hst.aau.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Measuring pain by computerized Visual Analog Scale Scoring (time frame: Baseline). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.

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