Positive patch test reactions to oxidized limonene: exposure and relevance
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Published on: May 21, 2019
Johanna Bråred Christensson1, Klaus E Andersen, Magnus Bruze
1Department of Dermatology, Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden; Dermatochemistry and Skin Allergy, Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden.
Background:
R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reaction to oxidized R-limonene.
Objective:
To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis.
Methods:
Oxidized R-limonene 3.0% (containing limonene hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed.
Results:
Overall, exposure to products containing limonene was found and assessed as being probably relevant for the patients' dermatitis in 36% of the limonene-allergic patients. In Barcelona and Copenhagen, > 70% of the patients were judged to have had an exposure to limonene assessed as relevant.
Conclusions:
Oxidized R-limonene is a common fragrance allergen, and limonene was frequently found in the labelling on the patients' products, and assessed as relevant for the patients' dermatitis. A large number of domestic and occupational sources for contact with R-limonene were identified.
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