Repeated Open Application Test (ROAT) Study With Hydroperoxides of Linalool

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. Exclusion criteria * Known or possible contact allergy to hydroperoxides of Linalool * Known contact allergy to other fragrance allergens * Active eczema or other known relevant skin diseases * Pregnancy or breast feeding * Treatment with topical corticosteroids or other immune suppressants on/near test areas within four weeks prior to study start. * Systemic immune-suppressant treatment within four weeks prior to study start. * UV exposure of test areas within three weeks prior to study start. * Participation in other clinical studies within four weeks prior to study start. * Unable to cooperate or communicate with the investigators.