About this trial
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 criteria
This trial accepts healthy volunteersQualifiers
Healthy men and women
18-60 years
Speak and understand English
Disqualifiers
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
Trial design
Crossover
Treatments tested in this trial
Histamine
Other interventionHistaminergic 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
Other intervention25 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.
Treatment groups
Trial outcomes
Primary outcomes
Reinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ).
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)
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)
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)
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".
Secondary outcomes
Assessment of itch
Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
Assessment of pain
Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.
Sponsors and contacts
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