ITCH
Conditions
Brief summary
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, three areas will be selected on each forearm of the subjects. Two areas will be treated with histamine, two with cowhage, and two with vehicle. One application of each substance will be conducted including the contagious itch component. During the 10 minutes of the application of the pruritogens, itch and pain will be continuously monitored using a VAS scale.
Interventions
OTHERHistamine
To deliver histamine, standard allergy skin prick test (SPT) lancets are applied
The spicules will be manually inserted. Approximately 30-35 spicules are gently rubbed into a 1 cm diameter skin area on the forearm/face
OTHERPlacebo
To deliver steril water, standard allergy skin prick test (SPT) lancets are applied
Sponsors
Aalborg University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measuring pain by computerized Visual Analog Scale Scoring | Immediately after the intervention | The investigators 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. |
| Measuring itch by computerized Visual Analog Scale Scoring | Immediately after the intervention | The investigators 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Learned Helplessness Scale (LHS) | Baseline | 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). |
| Depression, Anxiety, Stress Scale (DASS-21) | Baseline | 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 |
| Reinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ). | Baseline | The RST-PQ contains in total 65 items must be answered on a 4-point Likert (Strongly disagree → Strongly agree) |
| Pain Catastrophizing Scale (PCS). | Baseline | 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). |
| Difficulties in Emotion Regulation Scale Short Form (DERS-SF) | Baseline | 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) from almost never to almost always |
| Emotion Regulation Questionnaire (ERQ) | Baseline | 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). |
| Positive And Negative Affect Schedule (PANAS) | Baseline | Twenty words are associated with the subject's current feelings and have to be rated on a 5-points Likert-type scale from very slightly or not at all to extremely |
| Itch Catastrophizing Scale (ICS) | Baseline | 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). |
Countries
Denmark
Contacts
Primary ContactSilvia Lo Vecchio, PhD
Outcome results
None listed