| 1. |
- Hagvall, Lina, 1978, et al.
(författare)
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Patch testing with purified and oxidized citronellol
- 2020
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 83:5, s. 372-379
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Tidskriftsartikel (refereegranskat)abstract
- Background Citronellol is a commonly used fragrance terpene included in fragrance mix II. As with many other fragrance terpenes, citronellol is susceptible to autoxidation. Citronellol hydroperoxides are formed in large amounts and are the only oxidation products identified as sensitizers in oxidized citronellol. Aim To compare frequencies of contact allergy to purified and oxidized citronellol and to investigate the pattern of concomitant reactions to fragrance markers of the baseline series, oxidized linalool, and oxidized limonene. Methods A total of 658 dermatitis patients were patch tested with purified and oxidized citronellol at 2.0%, 4.0%, 6.0%, and 1.0%, 2.0%, 4.0%, 6.0% petrolatum, respectively. The irritant properties of purified and oxidized citronellol were studied before patch testing. Results Few irritant reactions were observed in the pretest. Purified citronellol detected positive reactions in 0.15%-0.31% of patients, while oxidized citronellol detected positive reactions in 0.61%-4.5%. Among patients reacting to oxidized citronellol, 34%-50% showed concomitant reactions to fragrance markers of the baseline series and 75%-91% to oxidized linalool or oxidized limonene. Conclusion Oxidized citronellol detects more cases of contact allergy than purified citronellol, and these cases are not all detected using fragrance mix II. Patch testing with oxidized citronellol will add to the tools in the diagnosis of fragrance allergy.
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| 2. |
- Andersch-Björkman, Ylva, et al.
(författare)
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Air-oxidized linalool elicits eczema in allergic patients-a repeated open application test study.
- 2014
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Ingår i: Contact dermatitis. - : Wiley. - 1600-0536 .- 0105-1873. ; 70:3, s. 129-38
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Tidskriftsartikel (refereegranskat)abstract
- Linalool is a commonly used fragrance terpene that forms potent sensitizers upon oxidation. In a recent multicentre study, we found that 7% of 2900 patients showed positive patch test reactions to oxidized linalool at 6.0%. No elicitation studies have been performed.
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| 3. |
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| 4. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Fragrance Allergens, Overview with a Focus on Recent Developments and Understanding of Abiotic and Biotic Activation
- 2016
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Ingår i: Cosmetics. - : MDPI AG. - 2079-9284. ; 3:2, s. 19-37
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Tidskriftsartikel (refereegranskat)abstract
- Fragrances and fragranced formulated products are ubiquitous in society. Contact allergies to fragrance chemicals are among the most common findings when patch-testing patients with suspected allergic contact dermatitis, as well as in studies of contact allergy in the general population. The routine test materials for diagnosing fragrance allergy consist mainly of established mixes of fragrance compounds and natural extracts. The situation is more complex as several fragrance compounds have been shown to be transformed by activation inside or outside the skin via abiotic and/or biotic activation, thus increasing the risk of sensitization. For these fragrance chemicals, the parent compound is often non-allergenic or a very weak allergen, but potent sensitizers will be formed which can cause contact allergy. This review shows a series of fragrance chemicals with well-documented abiotic and/or biotic activation that are indicative and illustrative examples of the general problem. Other important aspects include new technologies such as ethosomes which may enhance both sensitization and elicitation, the effect on sensitization by the mixtures of fragrances found in commercial products and the effect of antioxidants. A contact allergy to fragrances may severely affect quality of life and many patients have multiple allergies which further impact their situation. Further experimental and clinical research is needed to increase the safety for the consumer.
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| 5. |
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| 6. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Limonene hydroperoxide analogues differ in allergenic activity
- 2008
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 59:6, s. 344-352
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Tidskriftsartikel (refereegranskat)abstract
- Background: The fragrance terpene R-limonene is a very weak sensitizer but forms allergenic oxidation products upon contact with air. Oxidized (ox.) limonene is a frequent cause of contact allergy in clinical testing. Objectives: This study investigates the sensitizing potencies of ox. and non-ox. limonene and of structurally closely related limonene hydroperoxides. The clinical importance of the difference in sensitizing potency of two hydroperoxides in autoxidized limonene was studied. Patients/Methods: Ox. and non-ox. limonene were investigated in the murine local lymph node assay (LLNA). Limonene hydroperoxides were investigated using a modified LLNA involving non-pooled lymph nodes and statistical calculations; patch testing of patients with known contact allergy to ox. limonene was performed. Results: A marked increase in the sensitizing potency of ox. limonene compared with that of pure limonene was observed in the LLNA. One analogue, limonene-1-hydroperoxide, was a significantly more potent sensitizer than the other hydroperoxides and gave more positive test reactions in the allergic patients. Conclusions: The results support that hydroperoxides have a specific reactivity indicating that oxygen-centred radicals are important in hapten–protein complex formation of hydroperoxides. The primary oxidation products of ox. limonene, the hydroperoxides, have an important impact on the sensitizing capacity of the oxidation mixture.
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| 7. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Limonene hydroperoxide analogues show specific patch test reactions.
- 2014
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Ingår i: Contact dermatitis. - : Wiley. - 1600-0536 .- 0105-1873. ; 70:5, s. 291-299
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Tidskriftsartikel (refereegranskat)abstract
- The fragrance terpene R-limonene is a very weak sensitizer, but forms allergenic oxidation products upon contact with air. The primary oxidation products of oxidized limonene, the hydroperoxides, have an important impact on the sensitizing potency of the oxidation mixture. One analogue, limonene-1-hydroperoxide, was experimentally shown to be a significantly more potent sensitizer than limonene-2-hydroperoxide in the local lymph node assay with non-pooled lymph nodes.
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| 8. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Linalool - a significant contact sensitizer after air exposure
- 2010
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 62:1, s. 32-41
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Tidskriftsartikel (refereegranskat)abstract
- Background: Linalool is a widely used fragrance terpene. Pure linalool is not allergenic or a very weak allergen, but autoxidizes on air exposure and the oxidation products can cause contact allergy. Oxidized (ox.) linalool has previously been patch tested at a concentration of 2.0% in petrolatum (pet.) in 1511 patients, and 1.3% positive patch test reactions were observed. Objective: To investigate the optimal patch test concentration for detection of contact allergy to ox. linalool. Methods: Four concentrations of ox. linalool (2.0%, 4.0%, 6.0%, 11.0% pet.) were tested in 3418 consecutive dermatitis patients. Results: Ox. linalool 2.0%, 4.0%, 6.0%, and 11.0% pet. detected positive patch test reactions in 0.83%, 3.2%, 5.3%, and 7.2% of the tested patients, respectively. The doubtful reactions increased with rising concentrations but relatively less, giving 5.1%, 6.4%, and 7.3% doubtful reactions, respectively, for ox. linalool 4.0%, 6.0%, and 11.0% pet. Few irritative reactions were seen. Conclusions: Raising the patch test concentration for ox. linalool gave a better detection of contact allergy, as many as 5-7% positive patch test reactions were detected. We suggest a patch test concentration of ox. linalool 6.0% pet. for future patch testing, giving a dose per unit area of 2.4 mg/cm(2) when 20 mg test substance is tested in small Finn Chambers (R).
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| 9. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Oxidized limonene and oxidized linalool-concomitant contact allergy to common fragrance terpenes.
- 2016
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Ingår i: Contact dermatitis. - : Wiley. - 1600-0536 .- 0105-1873. ; 74:5, s. 273-80
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Tidskriftsartikel (refereegranskat)abstract
- Limonene and linalool are common fragrance terpenes. Both oxidized R-limonene and oxidized linalool have recently been patch tested in an international setting, showing contact allergy in 5.2% and 6.9% of dermatitis patients, respectively.
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| 10. |
- Hagvall, Lina, 1978, et al.
(författare)
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Concomitant reactions to geraniol and citral – due to cross reactivity?
- 2012
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Ingår i: Contact Dermatitis. - 1600-0536. ; 66:s2, s. 66-87
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Konferensbidrag (refereegranskat)abstract
- Background: Fragrance allergy is estimated as the second most common contact allergy in the western world, based on test results using the fragrance markers in the baseline series. One of these markers, fragrance mix (FM), contains geraniol at a concentration of 1%. Although about 10% of tested consecutive dermatitis patients react to FM, geraniol is responsible for only 5% of positive patch test reactions to the individual components of FM. However, we have shown that geraniol forms sensitizing compounds via autoxidation and skin metabolism. Geranial and neral, the two isomers in citral, are the major haptens formed in both of these activation pathways. Objectives: To investigate whether testing with oxidized (ox) geraniol detects more cases of contact allergy than testing with pure geraniol. The pattern of reactions to pure and ox geraniol, and the metabolites/autoxidation products geranial and neral was studied to investigate the importance of autoxidation or cutaneous metabolism in contact allergy to geraniol. Patients and methods: Pure and ox geraniol were tested at 2.0% pet in 2227 and 2179 consecutive patients, respectively. In parallel, geranial, neral and citral were tested in 2152, 1626, and 1055 consecutive patients, respectively. Results: Pure and ox geraniol detected positive patch test reactions in 0.13% and 0.55% of the patients, respectively. Eight of 11 patients with positive patch test reactions to ox geraniol also reacted to citral or its components. Relevance for the positive patch test reactions in relation to the patients´ dermatitis was found in 11 of 14 cases. Conclusions: Testing with ox geraniol could detect more cases of contact allergy to geraniol. The reaction pattern of the 14 cases presented indicates that both autoxidation and metabolism could be important in sensitization to geraniol. Concomitant reactions for geraniol and citral could be due to cross reactivity.
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