title: Oxidized citrus oil (R-limonene): a frequent skin sensitizer in Europe.
abstract: BACKGROUND
  Peel oil from citrus fruits consists of R-(+)-limonene, which is one of the most commonly used fragrance materials in technical products and in fine fragrances. This substance forms allergenic oxidation products during handling and storage.
  
  
  OBJECTIVE
  We wanted to study the frequency of allergic reactions to oxidized R-(+)-limonene in patients with dermatitis and find a suitable test preparation.
  
  
  METHODS
  Patch testing with oxidized R-(+)-limonene was performed on 2273 patients at 4 dermatology clinics in Europe.
  
  
  RESULTS
  Of the consecutive patients tested, 3.8% to 3.9% had positive reactions in two of the clinics; 6.5% had positive reactions in the third clinic; and 0.3% had positive reactions in the fourth clinic. A total of 63 patients showed positive reactions. In total, 57% of the patients did not react to fragrance mix or balsam of Peru. We recommend testing with 3% oxidized R-(+)-limonene in patients referred for patch testing.
  
  
  CONCLUSIONS
  The high frequency of oxidized limonene allergy provides clinical evidence for the European classification of R-(+)-limonene that contains oxidation products as skin sensitizers.
authors.affiliation: Occupational Dermatology, National Institute for Working Life, Stockholm, Sweden.
authors.forename: Mihály
authors.initials: M
authors.lastname: Matura
authors.forename: An
authors.initials: A
authors.lastname: Goossens
authors.forename: Olivia
authors.initials: O
authors.lastname: Bordalo
authors.forename: Begoña
authors.initials: B
authors.lastname: Garcia-Bravo
authors.forename: Kerstin
authors.initials: K
authors.lastname: Magnusson
authors.forename: Karin
authors.initials: K
authors.lastname: Wrangsjö
authors.forename: Ann-Therese
authors.initials: AT
authors.lastname: Karlberg
mesh_terms: D003358:Cosmetics; D053138:Cyclohexenes; D005060:Europe; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D000077222:Limonene; D008297:Male; D010328:Patch Tests; D013729:Terpenes / Q000276:immunology*
chemical_list: D003358:Cosmetics; D053138:Cyclohexenes; D013729:Terpenes; D000077222:Limonene