The study objective is to assess whether positive expectations, induced by verbal suggestions in an open-label design (i.e. knowing about the suggestions), can reduce itch during a short-term validated histamine test.
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
Het onderzoek wordt bij gezonde proefpersonen uitgevoerd. Uitkomsten uit deze lijn van onderzoek bieden nieuwe handvatten voor verklaringsmodellen en therapeutische interventies voor aandoeningen waarbij jeuk een symptoom is.
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary study parameter is self-reported mean itch during histamine
iontophoresis.
Secondary outcome
Secondary study outcomes include wheal size, flare response, skin temperature
and self-reported skin condition following histamine iontophoresis, as well as
scratching behaviour. In addition, effects on positive and negative affect and
generalized expectations will be explored. The possible influence of
psychological parameters on outcomes will be explored as well.
Background summary
The current evidence suggests that it might be possible to influence itch
through inducing positive expectations by verbal suggestions. There is a
growing body of literature that suggests that placebo effects can occur, even
when it is known that a given substance is inert. However, no study to date has
investigated whether suggestions can induce positive outcome expectations and
reduce itch, with participants knowing that expectations can reduce itch.
Study objective
The study objective is to assess whether positive expectations, induced by
verbal suggestions in an open-label design (i.e. knowing about the
suggestions), can reduce itch during a short-term validated histamine test.
Study design
A randomized, controlled, between-subjects study design will be applied.
Participants will be randomly assigned to 1) the verbal suggestions condition
(open-label positive verbal suggestions) or 2) the control condition (no
positive verbal suggestions). Participants will be invited for a single
session, during which they will be exposed to transdermal histamine
iontophoresis. Self-reported itch will be assessed during and following
histamine iontophoresis. Prior to the session, participants are asked to fill
in online questionnaires.
Intervention
Positive expectations will be induced by means of verbal suggestions in the
verbal suggestion condition.
Study burden and risks
Participants need to invest a total of approximately 1,5 hours in the study.
Given the relatively healthy study population, no adverse side effects are
expected. The symptoms of transdermal histamine iontophoresis (local swelling,
itch and flare) will disappear within several minutes to a maximum of 2 hours.
All other measurements are considered minimally invasive. Participants will
receive a reimbursement of 12,50 euros for participation in this study.
Wassenaarseweg 52
Leiden 2333 AK
NL
Wassenaarseweg 52
Leiden 2333 AK
NL
Age
Inclusion criteria
Between 18 and 35 years old; good understanding of written and spoken Dutch
Exclusion criteria
Refusal to give written informed consent; severe somatic or psychological morbidity (e.g. heart and lung diseases, or DSM-IV psychiatric disorders) that would adversely affect participant*s safety or study protocol; current chronic itch or pain complaints; current use of analgesics, anti-inflammatory drugs, antihistamines, antibiotics; pregnancy
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL54570.058.15 |