A negative breakdown test in a fragrance mix I‐positive patient does not rule out contact allergy to its fragrance constituents

Abstract

Background: In about half of the patients reacting positive to fragrance mix I (FM I), breakdown testing remains negative. This raises the question of whether the reaction to FM I is false-positive, or the breakdown test is false-negative. Objectives: To identify characteristics and sensitization patterns of patients positive to FM I, but not to its fragrance constituents. Patients and Methods: Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK) between 2005 and 2019. Three patient groups were defined according to their reaction pattern: Group I, FM I positive and ≥1 single fragrance positive in the breakdown test (n = 1912); Group II, FM I positive and breakdown test negative (n = 1318); Group III, FM I negative (n = 19 790).Results: Regarding the pattern of concomitant reactions to other fragrances, Group II had an intermediate position between Group I and Group III. In other respects (age and sex distribution, frequency of sensitization to non-fragrance baseline series allergens), Group II rather resembled Group I.Conclusions: Not every positive reaction to FM I in patients with negative breakdown tests is false-positive. There may be false-negative reactions to the single fragrance components when patch tested at 1% pet. Raising patch concentrations of some single fragrances is recommended.

Simultaneous patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes: An update from southern Sweden

“…As expected, the patch test results of fragrance mixes and their ingredients in this study were not precisely consistent with each other (Figures 3 and 4). This has been observed in some studies and remained a concerning problem 10,12,37 . The possible explanations were (1) false reactions 37 (either to the mixes or to their ingredients), (2) different test concentrations of the individuals in the mixes and their ingredients' test preparations 38,39 ; (3) some materials in the mixes might have a mild irritation effect and enhance absorption of other substances by disrupting the skin barrier when they are mixed; (4) a combination effect—a positive reaction to a mix might be a combination of multiple doubtful reactions to more than one ingredient, which might be read as doubtful or negative when tested with individual ingredients.…”

“…About half of patients with positive reactions to fragrance mixes did not react to any of their constituents (Figure 3). It has been suggested that the test preparations of individual fragrance allergens might need to be increased if the patients reacted to the mixes but did not react to their ingredients' preparations 37 . Because the concentrations in the preparations of individual ingredients were higher than in the mixes, additional cases could unquestionably be detected (Figure 4).…”

“…This has been observed in some studies and remained a concerning problem. 10,12,37 The possible explanations were (1) false reactions 37 (either to the mixes or to their ingredients), (2) different test concentrations of the individuals in the mixes and their ingredients' test preparations 38,39 ;…”

“…It has been suggested that the test preparations of individual fragrance allergens might need to be increased if the patients reacted to the mixes but did not react to their ingredients' preparations. 37 Because the concentrations in the preparations of individual ingredients were higher than in the mixes, additional cases could unquestionably be detected (Figure 4). From the figure, 30 of 81 positive reactions were further detected because the concentrations of the individual ingredient preparations in FM II are twice comparing to themselves in the mix.…”

Very late reactions in the patch test with fragrance mix I and oak moss absolute (Evernia prunastri, INCI): Data of the Information Network of Departments of Dermatology (IVDK)

“…Positive reactions to all single FMI constituents without positive reactions to the mix were observed rarely, but most often in OM positives. 8 One might speculate on different allergen content (eg, atranols) in-between the raw material used. Very late reactions were seen in 20 patients.…”