Allergen of the Year: Fragrance

Frances J. Storrs

Disclosures

Dermatitis. 2007;18(1):3-7. 

In This Article

A New Fragrance Mix

In 2005, a six-center European and Scandinavian study presented a new six-ingredient fragrance mix (fragrance mix II [FM II]).[12] Testing with a total concentration of 14% for its ingredients, the investigators found that 32% of all patients who had positive reactions to FM II had negative reactions to FM I.[12] Of patients with a "certain" fragrance history, 35% had positive reactions to FM II and negative reactions to FM I.

The constituents of FM II are as follows:

  1. Citronellol 0.5%

  2. Hydroxyisohexyl 3-cyclohexene carboxaldehyde (Lyral) 2.5%

  3. Hexyl cinnamal 5.0%

  4. Citral 1.0%

  5. Coumarin 2.5%

  6. Farnesol 2.5%

FM II is available from Chemotechnique Diagnostics AB (Malmö, Sweden and Hermal, Reing, Germany). It does not contain sorbitan sesquioleate.

Frosch and colleagues identified five of their FM II ingredients in 50 to 88% of 24 products obtained from 12 of their allergic patients. Only farnesol was not detected.[12] When the individual ingredients were tested separately, Lyral most often yielded positive reactions, hexyl cinnamal least often, and coumarin never. Only 48% of their patients who reacted positively to FM II reacted to at least one of the mix ingredients. Low-grade irritancy and frequent + reactions were common.

The percentage of positive reactions to individual mix ingredients, frequent irritancy, and low-grade positive reactions are equally common with FM I.[6,8,12] Mixes are always problematic. The failure of individual fragrance ingredients in either mix to reproduce positive reactions has long troubled patch testers and made them question the validity of these mixes. It helps to know of this reality when interpreting these patch tests. Concepts such as "quenching" or the development of new allergens in the mixes have satisfied no one.[6,13]

It is likely that as more is learned about the ingredients of fragrances in different countries, fragrance mixes will become more tailored to the country. For example, in a recent collection of 1,603 patients in North America who were patch-tested to investigate eczematous dermatitis, only 7 patients reacted to Lyral at a concentration of 5% (it is 2.5% in FM II). Of these 7 reactions, 5 were +, 1 was ++, and 1 was +++.[14] The intensity of fragrance reactions has been tied to the likelihood of relevance by other investigators.[5] Although the study by Frosch and colleagues found Lyral to be most often reactive in FM II. Lyral reactions are clearly uncommon in North America.[12,14]

Even though we in North America lack much of the precise chemical information collected by the Europeans, and even though we know fragrances differ in different countries, it is still likely that FM II will add to the information we collect from patch-testing our patients. The NACDG will add FM II to its 2007 standard tray, and I recommend this to the reader as well.

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