title: Categorization of fragrance contact allergens for prioritization of preventive measures: clinical and experimental data and consideration of structure-activity relationships.
abstract: Contact allergy to fragrances is still relatively common, affecting ∼ 16% of patients patch tested for suspected allergic contact dermatitis, considering all current screening allergens. The objective of the review is to systematically retrieve, evaluate and classify evidence on contact allergy to fragrances, in order to arrive at recommendations for targeting of primary and secondary prevention. Besides published evidence on contact allergy in humans, animal data (local lymph node assay), annual use volumes and structure-activity relationships (SARs) were considered for an algorithmic categorization of substances as contact allergens. A total of 54 individual chemicals and 28 natural extracts (essential oils) can be categorized as established contact allergens in humans, including all 26 substances previously identified as contact allergens (SCCNFP/0017/98). Twelve of the 54 individual chemicals are considered to be of special concern, owing to the high absolute number of reported cases of contact allergy (>100). Additionally, 18 single substances and one natural mixture are categorized as established contact allergens in animals. SARs, combined with limited human evidence, contributed to the categorization of a further 26 substances as likely contact allergens. In conclusion, the presence of 127 single fragrance substances and natural mixtures should, owing to their skin sensitizing properties, be disclosed, for example on the label. As an additional preventive measure, the maximum use concentration of 11 substances of special concern should be limited to 100 ppm. The substance hydroxyisohexyl 3-cyclohexene carboxaldehyde and the two ingredients chloroatranol and atranol in the natural extracts Evernia prunastri and Evernia furfuracea should not be present in cosmetic products.
authors.affiliation: Department of Medical Informatics, Biometry and Epidemiology, University of Erlangen/Nürnberg, 91054 Erlangen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Uter
authors.forename: Jeanne D
authors.initials: JD
authors.lastname: Johansen
authors.forename: Anna
authors.initials: A
authors.lastname: Börje
authors.forename: Ann-Therese
authors.initials: AT
authors.lastname: Karlberg
authors.forename: Carola
authors.initials: C
authors.lastname: Lidén
authors.forename: Suresh
authors.initials: S
authors.lastname: Rastogi
authors.forename: David
authors.initials: D
authors.lastname: Roberts
authors.forename: Ian R
authors.initials: IR
authors.lastname: White
mesh_terms: D000485:Allergens / Q000009:adverse effects / Q000145:classification*; D003257:Consumer Product Safety; D017449:Dermatitis, Allergic Contact / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D005060:Europe / Q000453:epidemiology; D006801:Humans; D010328:Patch Tests; D010476:Perfume / Q000009:adverse effects / Q000145:classification*; D013329:Structure-Activity Relationship
chemical_list: D000485:Allergens; D010476:Perfume
keywords: Directive 76/768/ECC; SCCS; fragrance allergens; labelling; scientific opinion