To determine whether we should add ascaridole to the patch test and to differentiate between a truely positive allergic reaction and an irritant reaction. What is the relevant patch test concentration of ascaridole?
ID
Source
Brief title
Condition
- Epidermal and dermal conditions
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
We will perform an epicutanous allergy test with ascaridole on the back of the
participants. The test results will be graded according to the guidelines of
the International Contact Dermatitis Research Group (ICDRG). This will result
in a -, +? , +, ++, +++ or IR (irritated) response.
The back of the participant will be photgraphed.
Secondary outcome
The questionnaire will be used to possibly clarify the relevance of a contact
allergy, thereupon the history of exposure will be labeled: certain, probable,
possible, unlikely/not. When a patient had reacted with an itching dermatitis
to at least one product containing tea tree oil and had reacted to other
alternatives, this was labeled *certain*. The category *Probable* existed of
patients, who had reacted to one or more products probably containing tea tree
oil, but a specific product had not been identified as the cause of a clinical
reaction. The third category was *Possible*; the patient had reacted to various
products with or without tea tree oil. Substances other than tea tree oil could
have been the cause of a reaction in this category of patients. If a patient
had never come in contact with products containing tea tree oil, the relevance
was labeled *Unlikely/ not*
Background summary
Tea tree oil is an increasingly popular ingredient in a variety of cosmetic and
over-the-counter healthcare products, including shampoos, massage oils and
creams. It has been shown to be active against a variety of bacteria, fungi,
viruses and mites. The tea tree oil is extracted from the leaves of the tea
tree (melaleuca alternifolia) via steam distillation.
It seems it causes contact sensitization and allergic contact dermatitis
reactions. It is import to report the oil undergoes photo oxidation leading to
the creation of degradation products that are moderate to strong sensitizers.
These must be considered responsible for the development of allergic reactions.
A degradation product of tea tree oil is Ascaridole. Ascaridole is a
monoterpene that is derived from oxidized α-terpene. Multiple studies show
ascaridole causes the positive reaction to the patch test of tee tree oil. It
is not clear at which concentration the reaction occur.
In a previous study (C.V. Bakker et al, Ascaridole, a sensitizing component of
tea tree oil, patch tested at 1% and 5% in two series of patients, Contact
Dermatitis 2011: 65: 239-248) is described how accidental maybe a positive test
reaction to ascaridole was declared as positive, though it was actual an
irritated reaction.
By testing this time with a lower concentration (1 and 2%) and to repeat the
higher concentration (5%) of ascaridole, it is possible to confirm or to
exclude the allergy.
We choose for the cocnentrations of 1%, 2% and 5% because this are the usual
concentrations for patch test concentrations, as provided bij Chemotechnique
Diagnostics, the world leader in patch testing.
Study objective
To determine whether we should add ascaridole to the patch test and to
differentiate between a truely positive allergic reaction and an irritant
reaction.
What is the relevant patch test concentration of ascaridole?
Study design
Observational study with invasive measurements
Study burden and risks
For each participant the study lasts one week, during which the participant
will wear a patch test on his back for 48 hours. During this time he ought to
keep the application site on his back dry. We will visit the participant four
times at a location of his choice. All the visits will take about 15 minutes.
During the first visit the participant will answer a questionnaire about
medication, pregnancy and skin diseases on the back and we will apply the
allergy test on the back. During the last visit the participant will answer a
questionnaire about exposure to ascaridole/ tea tree oil.
Because of the patch test on their back, participants may experience some
irritation on the back and there*s a small risk of active sensibilsation to
ascaridole, however most participants have probably allready been sensitized
because of the previous positive patch test result.
The participants have been tested in the past with an epicutanous allergy test
so they will know what to expect.
The study needs to be done in this selected group, because they have already
reacted to ascaridole.
Hanzeplein 1
Groningen 9713GZ
NL
Hanzeplein 1
Groningen 9713GZ
NL
Listed location countries
Age
Inclusion criteria
- Adulthood
- Legal competence
- Epicutanous allergy test in the UMCG between 01-05-2011 and 30-09-2012
- Positive reaction (at least +) for ascaridole or doubtfull reaction for 1% or irritant reaction for 5%
Exclusion criteria
- Angry back in the past (fals positive reaction to some patch test substances, be accompanied by heavy itch)
- Active skin disease on the back
- Use of immunosuppressive drugs up to six weeks before inclusion
- Pregnancy(wish)
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 | NL41035.042.12 |