Allergic Contact Dermatitis
Conditions
Brief summary
Linalool is currently one of the most used fragrance substances in cosmetic and household products. Previous studies report a high prevalence (5.9-11.7%) of contact allergy to hydroperoxides of linalool (Lin-OOH)1.0% in pet. among patch tested patients. The optimal test concentration of Lin-OOH in patch tests is not known and requires further investigation. It is of great importance to establish the optimal test concentration and elicitation threshold of Lin-OOH to improve diagnosis and prevent development of Allergic Contact Dermatitis (ACD). We want to mimic real-life exposure to Lin-OOH, by conducting a ROAT (Repeated Open Application Test) study, on 40 adult participants (20 patients with confirmed contact allergy to Lin-OOH, and 20 healthy participants) to low doses of Lin-OOH using a simulated perfume, during a maximum of 21 days of exposure. With this knowledge, we aim to: 1. Establish the optimal patch test concentration to diagnose ACD to Lin-OOH 2. In case of confirmed contact allergy, examine the threshold value for the development of ACD upon daily exposure to a simulated leave-on cosmetic product
Interventions
DIAGNOSTIC_TESTROAT
Repeated Open Application Test
Sponsors
National Allergy Research Center, Denmark
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 110 Years
Healthy volunteers
Yes
Inclusion criteria
Allergic participants: 1. Inclusion criteria * Positive (at least one reading) or doubtful patch test (at least two readings) result to hydroperoxides of Linalool within the last ten years * Aged 18 years or older * Received written and verbal information of the study * Signed written consent form 2.
Exclusion criteria
* Active eczema in test areas (volar forearms) * Pregnancy or breast feeding * Treatment with topical corticosteroids or other immune suppressants on/near test areas within two weeks prior to study start * Systemic immune-suppressant treatment within seven days prior to study start * UV exposure of test areas within three weeks prior to study start * Unable to cooperate or communicate with the investigators Healthy controls: 1. Inclusion criteria * Aged 18 years or older * Received written and verbal information of the study * Signed written consent form 2.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Establish the optimal patch test concentration to diagnose allergic contact dermatitis to hydroperoxides of linalool via a Repeated Open Application Test | 6 months | Establish the optimal patch test concentration to diagnose allergic contact dermatitis to hydroperoxides of linalool via Repeated Open Application Test |
| In case of confirmed contact allergy, examine the threshold value for the development of ACD upon daily exposure to a simulated leave-on cosmetic product | 6 months | In case of confirmed contact allergy, examine the threshold value for the development of ACD upon daily exposure to a simulated leave-on cosmetic product |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The Lin-OOH chemicals can penetrate the skin barrier and reside in the local skin tissue | 12 months | Chemical analysis of skin punch biopsies from the exposed skin of the patients' lower back: time of flight secondary ion mass spectrometry (ToF-SIMS) analysis of Lin-OOH in the skin. |
Outcome results
None listed