CD07 Cananga oil and ylang ylang oil: different haptens but with the same INCI name. The importance of patch testing to both

Abstract Cananga oil and ylang ylang oil are essentials oils used in perfumed products such as cosmetics, soaps and perfumery. The haptens ‘cananga oil, C-002’ and ‘ylang ylang oil (Cananga odorata), Y-001’ are available from Chemotechnique for patch testing. The preparations are steam distilled from flowers of the cultivars Cananga odorata macrophylla (C-002 cananga oil) and Cananga odorata genuine (Y-001 ylang ylang). The two haptens have different Chemical Abstracts Service (CAS) registry numbers – unique identifiers assigned to chemicals described in scientific literature, but share the same International Nomenclature of Cosmetic Ingredients (INCI) name, that is Cananga odorata, although compositional data reveals limited concordance. Between 2008 and 2024, we patch tested (in a targeted manner) 1059 patients to a fragrance and essential oil series including Y-001 and C-002, recording the results on a database. We reviewed our results, looking at the frequency of positives, notably to determine overlap, and hence whether testing to both is required. Most of those tested were female (82%), and the median age was 44 years. Facial involvement was reported in 56%. We found allergic positives in 11 (+/++/+++) to Y-001 (1.04%), 10 to Y-001 alone (0.94%), five (+) to C-002 (0.47%) and four (0.38%) to C-002 alone. One patient was positive to both Y-001 and C-002. One woman reacted to her own ylang ylang oil (cultivar not declared) – she was negative to Y-001 but positive to C-002. Fourteen (93%) of those positive to either Y-001 or C-002 reacted to at least one other fragrance (all of the Y-001 group; four of five of the C-002 group) – see the Table below. However, three were negative to fragrance markers in the British Standard Series. The 1% pickup rate for Y-001 supports its inclusion in a targeted fragrance series. Minimal concomitant reactions to C-002 – only one of 11 – means that both Y-001 and C-002 should be tested. They seem to have different constituent allergens. If only the British Standard Series had been used, contact allergy would have been missed in a significant proportion of cases.TablePositive reactions to other allergens in those testing positive to Y-001 or C-002 Positive to Y-001 (n = 11)Positive to C-002 (n = 5)Fragrance mix I74Fragrance mix II10OH- linalool 0.5/1%02OH- limonene00Myroxylon pereirae62HICC (hydroxyisohexyl 3-cyclohexene carboxaldehyde)10Isoeugenol74Eugenol22Oakmoss absolute30Balsam of Tolu61Clove oil33Lemon grass oil33Neroli oil20Lavender absolute10Cedarwood oil32Tea tree oil11