Contact allergy to essential oils cannot always be predicted from allergy to fragrance markers in the baseline series

Between January 2008 and June 2014, a study involving 471 patients tested for allergies to 14 essential oils and 2104 patients for Melaleuca alternifolia oil to assess if contact allergies to essential oils could be overlooked when only common fragrance markers were used. The study found that 34 patients had a positive reaction to at least one essential oil, with 11 of these showing no reaction to the six fragrance markers in the baseline series. This suggests that allergies to certain essential oils might not be detected through standard fragrance marker testing. The study recommends additional patch testing with essential oils and careful examination of 'natural' products for potential allergens. It also notes the importance of clear labeling of essential oils in products and the consideration of including oxidized forms of limonene and linalool in baseline series due to their allergenic potential.