Frequency of false‐negative reactions to the fragrance mix

Abstract

To estimate the frequency of false-negative reactions to the fragrance mix, the 8 constituents of the mix in concentrations of 5% (2% for cinnamic aldehyde) were added to the European standard series for routine testing. Patients with positive reactions to individual ingredients in the absence of a reaction to the mix were retested with serial dilutions. In a 4-month period, 677 patients were tested. 61 (9%) reacted to the mix and to 1 or more of the ingredients. 4 patients (0.6% of all patients tested and 6.2% of the patients allergic to fragrances) had false-negative reactions to the mix. They were allergic to cinnamic alcohol, geraniol, isoeugenol and oak moss (1 reaction each), in the absence of a reaction to the fragrance mix. It is concluded that the currently used concentration of the mix (8 x 1%) not infrequently results in false-negative reactions, and that further research should be done to overcome this problem.

Adverse reactions to fragrances

“…Previously (90), these authors had found that, of 179 patients suspected of cosmetic allergy, 13 reacted to ingredients of the mix tested at a higher concentration (7Xisoeugenol, 4Xoak moss, 1 X geraniol, and 1 combination), in the absence of a positive reaction to the mix itself. In the more recent study (89), patients with a negative reaction to the mix, but a positive reaction to 1 or more ingredients (5% pet. without SSO, cinnamic aldehyde 2% pet.…”

“…Of 677 patients tested, 6 had a positive reaction to ingredients, but a negative reaction to the mix. With serial dilution tests, 4 (0.6% of all patients and 6.2% of all fragrance-sensitive patients) had positive reactions to cinnamic alcohol, geraniol, isoeugenol and oak moss, I reaction each, which indicated that false-negative reactions to the mix occurred in them (89). Although these %s are rather small, the authors state that, given the large number of patients allergic to perfumes, several fragrancesensitive patients allergic to ingredients of the mix are missed with the mix of current composition.…”

“…The currently used mix causes false-positive (irritant) (87,88), but also false-negative reactions (89,90).…”

“…The test concentration in testing the individual constituents may be too low (89,90,93), as: (a) the mix contains chemically related substances, which may cross-react; (b) unrelated allergens in combination, as in the mix, may have a lowering effect on the concentration needed for the individual allergens to elicit reactions (113); (c) the absorption of the constituents in the mix may be enhanced by the presence of the emulsifier sorbitan sesquioleate; (d) a marginally irritant constituent in the mix may enhance the absorption of other constituents.…”

“…From the discussion above, it is quite clear that the currently used fragrance mix (8 X 1% with 5% sorbitan sesquioleate) is very useful but not ideal. It causes irritant reactions (87,88), irrelevant positive reactions (88,93,103,112), false-negative reactions (89,90), and leaves 20-30% of fragrance sensitivities undetected (1 0). Therefore, future research should be directed at both optimizing the test concentration of the mix and its ingredients and at finding more suitable allergens for a screening fragrance mix (89).…”