Mechanisms Underlying the Placebo Effect in Both Histaminergic and Non-histaminergic Itch
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Histamine, Cowhage.
- Who it may be relevant to
- Registry conditions: ITCH. Basic parameters: 18 years — 60 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Denmark
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Pain and Itch Neuromodulation: Effects of Offset Analgesia, Placebo, and Nocebo and Topographical Distribution of Itch and Pain Receptors
Overview
The study consists of one experimental session of approximately 1½ hours. 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. Afterwards, two areas will be selected on each forearm of the subjects. The four areas will be treated with the same vehicle cream for 20 minutes, in order to test the placebo effect. At the end of the cream application, two areas will be randomly treated with histamine while cowhage will be applied on the other two areas. During the 10 minutes of the application of the pruritogens, itch and pain will be continuously monitored using a Visual Analog Scale.
Interventions
- Other Histamine
To deliver histamine, standard allergy skin prick test (SPT) lancets are applied - Other Cowhage
The spicules will be manually inserted. Approximately 30-35 spicules are gently rubbed into a 1 cm diameter skin area on the forearm/face
Primary outcome measures
- Measuring pain by computerized Visual Analog Scale Scoring [Time frame: Immediately after the intervention]
- Measuring itch by computerized Visual Analog Scale Scoring [Time frame: Immediately after the intervention]
Secondary outcome measures (8)
- Pain Catastrophizing Scale (PCS). [Time frame: Baseline]
- Itch Catastrophizing Scale (ICS). [Time frame: Baseline]
- Learned Helplessness Scale (LHS) [Time frame: Baseline]
- Depression, Anxiety, Stress Scale (DASS-21) [Time frame: Baseline]
- Reinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ). [Time frame: Baseline]
- Positive And Negative Affect Schedule (PANAS) [Time frame: Baseline]
- Difficulties in Emotion Regulation Scale Short Form (DERS-SF) [Time frame: Baseline]
- Emotion Regulation Questionnaire (ERQ [Time frame: Baseline]
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
Denmark · 1 center
- Aalborg University — Gistrup
Identifiers
NCT: NCT07247695 · N-20250017 Project 2