Histamine: Histaminergic itch will be evoked by a 1% histamine solution. A droplet of histamine solution will be placed on the predetermined area on the forearm, and the SPT lancet will be pierced through the histamine with 120 g of pressure for 1-2 seconds.
Cowhage: 25 spicules will be inserted in the center of the predefined skin area on the mandibular area. The spicules will be gently rubbed for 15-20 seconds in circular motion to facilitate epidermal penetration.
Study summary
This project aims to investigate the relationship between different dimensions of catastrophizing (rumination, magnification, and helplessness) as well as some specific personality traits related to catastrophizing tendencies like anxiety sensitivity and fear sensitivity in the modulation of itch and pain intensities in an experimental setting.
Eligibility
Sex
ALL
Min age
18 Years
Max age
60 Years
Healthy volunteers
Accepted
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 addictive drugs
* Previous or current history of neurological (e.g. neuropathy), immunological (e.g. asthma, immune deficiencies, arthritis), musculoskeletal (e.g. muscular pain in the upper extremities,), cardiac disorder, or mental illnesses that may affect the results
* Lack of ability to cooperate
* Current use of medications that may affect the trial such as antihistamines, antipsychotics, and pain killers, as well as systemic or topical steroids
* Skin diseases (e.g. atopic dermatitis, pruritus nodularis, eczema, psoriasis)
* Moles, scars, or tattoos in the area to be treated or tested.
* Consumption of alcohol or painkillers 24 hours before the study days and between these
* Acute or chronic pain
* Participation in other trials within one week of study entry (four weeks in the case of pharmaceutical trials)
Primary outcome measure(s)
Reinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ). — Baseline 1st session The Reinforcement Sensitivity Theory - Personality Questionnaire contains the following subscales: the Fight-Flight-Freeze System (FFFS, 10 items); the Behavioral Inhibition System (BIS, 23 items); and the Behavioral Approach System (BAS, 32 items). In total, 65 items have to be answered on a 4-point Likert-type scale ranging from 1 (not at all) to 4 (Highly).
The Pittsburg Sleep Quality Index (PSQI) — Baseline 1st session The PSQI consists of 19 items generating seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The seven component scores can be summarized in a global score ranging from zero to 21 with higher scores reflecting a worse overall quality of sleep.
Depression, Anxiety, Stress Scale (DASS-21) — Baseline 1st session 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"
Positive And Negative Affect Schedule (PANAS) — Baseline 1st session PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement".
Pain Catastrophizing Scale (PCS). — 10 minutes after every itch induction on 1st session 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).
Itch Catastrophizing Scale (ICS). — 10 minutes after every itch induction on 1st session 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).
Learned Helplessness Scale (LHS) — 10 minutes after every itch induction on 1st session 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).
Positive And Negative Affect Schedule (PANAS) — 10 minutes after every itch induction on 1st session PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement".
Depression, Anxiety, Stress Scale (DASS-21) — Baseline 2nd session (3 days after 1st session) 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"
Positive And Negative Affect Schedule (PANAS) — Baseline 2nd session (3 days after 1st session) PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement"
Pain Catastrophizing Scale (PCS). — 10 minutes after every itch induction on 2nd session (3 days after 1st session) 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.
Itch Catastrophizing Scale (ICS). — 10 minutes after every itch induction on 2nd session (3 days after 1st session) 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.
Learned Helplessness Scale (LHS) — 10 minutes after every itch induction on 2nd session (3 days after 1st session) 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).
Positive And Negative Affect Schedule (PANAS) — 10 minutes after every itch induction on 2nd session (3 days after 1st session) PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement"
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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