Allergy to oxidized limonene and linalool is frequent in the U.K.

Abstract

This large, multicentre U.K. audit shows a significant rate of allergy to the hydroperoxides of limonene and linalool plus a high rate of irritant reactions. Testing to the oxidized forms alone captures the majority (97·0%; 411 of 422) of positive reactions; testing to nonoxidized terpenes appears to be less useful. We recommend that the hydroperoxides of limonene and linalool be added to an extended baseline patch test series.

Contact sensitization to limonene and linalool hydroperoxides in Spain: a GEIDAC* prospective study

“…Another interesting finding from our study is that 25% (74/292) of the patients with positive patch test reactions had simultaneous reactions to both terpene hydroperoxides, with similar results being obtained for all test concentrations. Similar values were also found in two recent multicentre studies . In other words, the majority of patients (∼75%) reacted only to one of the hydroperoxides, supporting the specificity of the reactions.…”

“…Regarding sensitization, no patients were, to our knowledge, actively sensitized during the present study, as no cases of late‐appearing reactions were reported. On the basis of these results, and according to previous recommendations , it seems that patch test preparations of Lim‐OOHs 0.3% pet. and Lin‐OOHs 1.0% pet.…”

“…Patch testing with non‐oxidized terpenes has proven to be a less useful screening method for detecting contact allergy to limonene and linalool. In a previous study from the United Kingdom, only 0.2% of the patients had positive reactions to stabilized (non‐oxidized) limonene, and 0.3% to stabilized linalool . Similarly, an Information Network of Departments of Dermatology study found that only 0.1% of the patients reacted to limonene and 0.3% to linalool, both of which were not deliberately oxidized .…”

“…and 5.9% to Lin‐OOHs 1.0% pet. , and in a recent international multicentre study including nine clinics in Australia, Denmark, Singapore, Spain, Sweden, and the United Kingdom, with 5.2% of the patients having positive reactions to oxidized limonene 3.0% pet. (containing 0.33% Lim‐OOHs) and 6.9% to oxidized linalool 6.0% pet.…”

Oxidation products and the skin – the effect of hydroperoxides

“…Patch test studies have shown the overall frequencies of contact allergy to different oxidized fragrance compounds to range between 0.1% and 8% of the tested patients . These frequencies are largely comparable to the frequencies of reactions observed for fragrance mix I and fragrance mix II in the established baseline series for the diagnosis of contact allergy .…”