Non-mix fragrances are top sensitizers in consecutive dermatitis patients - a cross-sectional study of the 26 EU-labelled fragrance allergens

Fragrance allergens in cosmetic products marketed for children in Denmark

BACKGROUND

Fragrances are among the most common contact allergens in children. Cosmetic products are the most frequent source of skin exposure.

OBJECTIVE

To investigate exposure to fragrance allergens among Danish children, based on a sample of 1179 cosmetic products marketed for children.

METHODS

Information regarding cosmetic products marketed to children was obtained using a non-profit smartphone application registry, with data from December 2015 to November 2022.

RESULTS

The number of validated products was 26  537, of which 1349 marketed for children. After elimination of duplicates, 1179 (4.4%) individual products remained. The majority 53.8% (634/1179) of the products were fragranced. The highest frequency of declared fragrances was found in 'Facial care'-products: 93.0% (80/86), of which 97.7% were lip balms. The highest number of labelled fragrances in one single product (n = 16) was found in a baby perfume. Fragrance mix I (FMI) or II (FMII) allergens were found in 25.3% (298/1179) of the products. Limonene and linalool were the two most frequently labelled fragrance allergens.

CONCLUSION

Children can be exposed to a vast number of fragrance allergens from scented cosmetic products. Allergens from FM I and FMII are widely used in cosmetic products marketed to children. Patch testing with FMI and FMII remains relevant in children.

Patch testing hydroperoxides of limonene and linalool in consecutive patients-Results of the IVDK 2018-2020

BACKGROUND

Hydroperoxides of limonene (Lim-OOHs) and linalool (Lin-OOHs) are potent contact sensitizers.

OBJECTIVES

To investigate the prevalence of positive patch test (PT) reactions to Lim-OOHs and Lin-OOHs in consecutive patients, their demographic factors and concomitant reactions.

METHODS

Between 7/2018 and 12/2020, Lim-OOHs 0.3% pet. and Lin-OOHs 1% pet. were patch tested in 5511 consecutive patients. We assessed PT reactivity and analysed data from patients with either positive or negative PTs to Lim-OOHs and Lin-OOHs.

RESULTS

Positive PT results to Lim-OOHs (n = 170, 3.1%) and Lin-OOHs (n = 483, 8.8%) were frequent. Most of the positive reactions were weak (LimOOHs n = 134/LinOOHs n = 429), and even more frequently, doubtful (n = 252/n = 578) or irritant reactions (n = 81/n = 178) were documented. PT reactivity to Lim-OOHs and Lin-OOHs was increased in patients with irritant reactions to sodium lauryl sulphate (SLS). The proportion of leg dermatitis and concomitant positive reactions to fragrances and essential oils was increased in patients with reactivity to these hydroperoxides.

CONCLUSION

The observed reaction pattern suggests that both test preparations display an irritant potential with an increased risk of false positive reactions. Preparations should be chemically monitored in order to reduce irritancy. Mindful interpretation of PT results and aimed patch testing of lower concentrations is recommended.

Patch test results with the European baseline series, 2019/20-Joint European results of the ESSCA and the EBS working groups of the ESCD, and the GEIDAC

BACKGROUND

Continual analyses of patch test results with the European baseline series (EBS) serve both contact allergy surveillance and auditing the value of included allergens.

OBJECTIVES

To present results of current EBS patch testing, obtained in 53 departments in 13 European countries during 2019 and 2020.

METHODS

Anonymised or pseudonymised individual data and partly aggregated data on demographic/clinical characteristics and patch test rest results with the EBS were prospectively collected and centrally pooled and analysed.

RESULTS

In 2019 and 2020, 22 581 patients were patch tested with the EBS. Sensitization to nickel remained most common (19.8 [19.2-20.4]% positivity [95% confidence interval]). Fragrance mix I and Myroxylon pereirae yielded very similar results with 6.80 (6.43-7.19)% and 6.62 (6.25-7.00)% positivity, respectively. Formaldehyde at 2% aq. yielded almost one percentage point more positive reactions than 1% concentration (2.49 [2.16-2.85]% vs. 1.59 [1.33-1.88]); methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI alone up to around 5% positives. Among the new additions, propolis was most commonly positive (3.48 [3.16-3.82]%), followed by 2-hydroxyethyl methacrylate (2.32 [2.0-2.68]%).

CONCLUSION

Ongoing surveillance on the prevalence of contact sensitization contributes to an up-to-date baseline series containing the most frequent and/or relevant contact sensitizers for routine patch testing in Europe.

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

Background

Regularly updating the prevalence of fragrance contact allergy (CA) is important. Patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes (FMs) is still debated.

Objectives

To update the prevalence and clinical characteristics of patients with fragrance CA. To establish the results of patch testing with individual allergens of FMs.

Methods

A retrospective analysis of 3539 patients with dermatitis who were patch tested with the baseline series and FMs ingredients during 2016 to 2020 was performed.

Results

The prevalence of fragrance CA was 13%. About 10% of these patients with fragrance CA would be missed if the individual ingredients were not tested. Unlike hydroxyisohexyl 3‐cyclohexene carboxaldehyde, there was no decreasing trend of CA to Evernia prunastri (oakmoss) extract after the EU regulation came into force. Patients with CA from only one ingredient of the mixes or having a weak positive reaction to the ingredients were significantly missed when tested with only the fragrance markers in the baseline series.

Conclusions

Patch testing with individual fragrance allergens is crucial for experts to expand knowledge in the fragrance CA field. The concentrations of the allergens in FMs may need to be adjusted to detect patients with fragrance CA, since some were significantly overlooked.

Limonene and linalool hydroperoxides review: pros and cons for routine patch testing

Limonene and linalool are among the most common fragrance terpenes used in products of everyday life. They are pre-haptens forming hydroperoxides (Lim-OOHs, Lin-OOHs) upon oxidation inducing frequent positive patch test reactions in patients with dermatitis. Still, they are not yet routinely tested in Europe. This review evaluates the patch testing experience with Lim-OOHs and Lin-OOHs by answering key questions such as whether hydroperoxide patch testing is warranted, understand difficulties or challenges related to the reading and interpretation of hydroperoxide patch test results with currently available material, assessing their relevance. Studies are increasingly pointing out to high percentages of positive reactions in patients consecutively patch tested with these oxidized products. An association between a positive clinical history and a strong patch test reaction has been described, but problems with doubtful/irritant reactions have also been reported. Considering the high frequencies of relevant positive reactions, the incorporation of Lim-OOHs 0.3% and Lin-OOHs 1% in the baseline series could be discussed and is maybe justified. Since exposure, sensitization and elicitation limits of Lim-OOHs and Lin-OOHs in the products still need to be better determined, an assessment of previous exposure, possible sensitizations and reactions may help to improve the clinical assessment. This article is protected by copyright. All rights reserved.

What is the added value of patch testing with 30 fragrance allergens in addition to the European baseline series?

Background

Patch testing with the fragrance allergy markers in the European baseline series (EBS) does not identify all patients with fragrance allergy. Hydroperoxides of linalool and limonene have been shown to be useful allergens in detecting fragrance sensitization.

Objectives

To evaluate the added value of testing with 30 fragrance allergens in addition to the EBS.

Methods

All patients with suspected fragrance allergy who underwent patch testing at the Amsterdam University Medical Centers between November 2019 and January 2021 to the EBS and fragrance series were included.

Results

Of 323 patients tested, 162 (50.2%) were found to be fragrance sensitized. The most sensitizing single allergens were the hydroperoxides of linalool (1.0 and 0.5% pet.) and limonene (0.3 and 0.2% pet.). Testing with the hydroperoxides of linalool and limonene identified 62 fragrance‐sensitized patients (38.3%) who could not be detected by the common fragrance markers. Of all fragrance‐sensitized patients, 21 (13.0%) would have been missed when not testing with the fragrance series.

Conclusions

Patch testing with the fragrance series in addition to the EBS is valuable. To reduce the risk of false‐negative reactions, it is advisable to test the hydroperoxides of linalool and limonene.

Highlights

Of the 323 patients with suspected fragrance allergy, 162 (50.2%) were found to be fragrance sensitized.

Testing with the hydroperoxides of linalool and limonene identified 62 fragrance‐sensitized patients (38.3%) who could not be detected by the European baseline series (EBS) fragrance markers. When not tested with the fragrance series, 21 (13.0%) of the sensitized patients would have been missed.

Routinely performing patch testing with the fragrance series in addition to linalool and limonene hydroperoxide as part of the EBS is recommended.

European patch test results with audit allergens as candidates for inclusion in the European Baseline Series, 2019/20 - Joint results of the ESSCAA and the EBSB working groups of the ESCD, and the GEIDACC

BACKGROUND

In 2019, a number of allergens (haptens), henceforth, 'the audit allergens,' were considered as potential additions to the European baseline series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5 or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments, too.

OBJECTIVES

To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe.

METHODS

Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the ESSCA testing these, as well as further collaborators from the EBS working group of the ESCD, and the Spanish GEIDAC. As patch test outcome, reactions between day (D) 3 and D5 were considered.

RESULTS

Altogether n=12403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74 (8.14-9.37)), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41 (4.95-5.89)). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72 (4.2-5.28), followed by sodium metabisulfite 1% pet. (3.75 (3.32-4.23)) and Compositae mix 5% pet. (2.31 (1.84-2.87). For some allergens, clinical relevance was frequently difficult to ascertain.

CONCLUSIONS

Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion among the ESCD members and ultimately decision on their implementation into routine testing. This article is protected by copyright. All rights reserved.

Fragrance, Sunscreens, Botanicals, and Potential Allergens in Bestseller 'Fairness' Creams in the Indian Market: A Consumer Exposure Study

Background

The skin lightening industry has seen exponential growth in India. Consumers often present to the dermatologist with adverse cutaneous reactions to these 'fairness' (skin lightening) creams. The composition of these creams has not received sufficient attention.

Objective

To identify fragrance, sunscreens, botanicals and potential allergens in the bestseller 'fairness' creams available in the Indian market.

Methods

Twenty fairness (or whitening or lightening) creams were selected based on the 'bestseller' creams of one of the largest electronic commerce websites in India, and availability in local stores and unlabelled brands were excluded. Fragrance, sunscreens, botanicals and potential allergens were identified from the ingredient labels.

Results

Twenty bestseller fairness creams were included. The number of the listed ingredients in the fairness creams ranged from 6 to 49 (mean = 32.2). The most frequently listed ingredients included water, fragrance or parfum, glycerin, tocopherol/tocopherylacetate and titanium dioxide. Hydroquinone, monobenzyl hydroquinone, corticosteroids, tretinoin and mercury were not listed in any of the creams. Unspecified fragrance was listed in 19 (95%) creams and linalool (8,40%) was the most frequent specified fragrance. Titanium dioxide (14, 70 %) was the most common inorganic sunscreen and ethylhexyl methoxycinnamate (12 creams or 60% of creams) was the most common organic sunscreen. Twenty-seven botanicals were identified. Eight ingredients were potential allergens according to the Indian Cosmetic and Fragrance Series. The cost of the creams ranged from 95 to 1,095 in Indian rupees (mean 300.5).

Conclusions

Consumers are exposed to a vast range of compounds in the quest for a lighter skin tone. Several potential allergens, particularly fragrance allergens, are present in addition to the eight allergens that were identified with the Indian Cosmetic and Fragrance Series. Increased awareness of the composition of skin lightening creams available in the market and strict regulation of these creams is needed.

Stratum corneum levels of inflammatory mediators and natural moisturizing factor in patch test reactions to thiurams and fragrances and their possible role in discrimination between irritant and allergic reactions to hapten mixtures

BACKGROUND

Patch test (PT) reactions to thiuram mix (TM) and fragrance mix (FM) I or II without concomitant reactions to their single constituents are potentially caused by the irritant properties of the mixes.

OBJECTIVE

Comparing inflammatory profiles of PT reactions to TM, FM I, FM II, and their constituents and assessing their potential in discrimination of irritant and allergic reactions.

PATIENTS AND METHODS

Levels of 14 cytokines and natural moisturizing factor (NMF) were determined in stratum corneum samples collected from PT reactions to TM, FM I or II, their constituents, and petrolatum (pet.) control sites in 36 individuals.

RESULTS

Levels of interleukin (IL)-16, chemokine (CXC motif) ligand (CXCL) 8, CXCL10, chemokine (CC motif) ligand (CCL) 17, and CCL22 were significantly increased in reactions (+, ++) to thiurams and fragrances compared to their petrolatum. controls, except for PT reactions to FM I/II with negative breakdown testing in which, however, decreased levels of NMF were observed. In doubtful reactions to FM I/II with negative breakdown testing, NMF was significantly lower than in petrolatum controls.

CONCLUSIONS

PT reactions to thiurams and fragrances indicate a Th2-skewed inflammation. The inflammatory profiles suggest that weak or doubtful FM I/II reactions without accompanying reaction to a constituent were irritant. IL-16 might be suitable to distinguish irritant from allergic reaction.

Prevalence, concomitant reactions, and factors associated with fragrance allergy in Thailand

BACKGROUND

Fragrances are the most common cause of cosmetic contact allergy. Up-to-date information on contact allergy frequencies and relevance aids primary and secondary preventive measures.

OBJECTIVES

To determine the prevalence, associated factors, and concomitant reactions in fragrance allergy among Thais.

METHODS

This retrospective study collected data from 2012 to 2019. The patient characteristics of fragrance and nonfragrance allergy groups were compared. Concurrent positive reactions to fragrance allergens (fragrance mix [FM] I, FM II, Myroxylon pereirae resin and hydroxyisohexyl 3-cyclohexene carboxaldehyde) and other baseline-series allergens were analysed.

RESULTS

Of 1032 patients, 175 (17.0%) had fragrance allergy, with 57.7% of clinical relevance. FM I showed the highest prevalence (9.4%). The associated factors were being elderly, lesions on the extremities, metal allergy history, and long dermatitis duration. Contact allergies to epoxy resin and Compositae plants were significantly associated with fragrance allergy with an odds ratio of 5.95 (95% confidence interval [CI]: 5.21-6.80) and an odds ratio of 4.42 (95% CI: 1.58-12.36), respectively. No significant associations between colophonium (previously proposed as a fragrance marker) and fragrance allergens were found.

CONCLUSIONS

The prevalence of fragrance contact allergy remains high and should be considered in old patients presenting with long-standing eczema on the extremities. Unlike reports from other countries, varied, significant, concomitant reactions were observed.

Developing a cosmetic series: Results from the ESSCA network, 2009-2018

BACKGROUND

There is considerable variability across European patch test centres as to which allergens are included in local and national cosmetics series.

OBJECTIVES

To propose a standardized, evidence-based cosmetic series for Europe based on up-to-date analysis of relevant contact allergens.

METHODS

We collated data from the European Surveillance System on Contact Allergies (ESSCA) from 2009 to 2018 to determine which cosmetic allergens produce a high yield of contact allergy. Contact allergens with a prevalence of >0.3% that were considered relevant were included. Rare contact allergens were excluded if deemed no longer relevant or added to a supplemental cosmetic series for further analysis.

RESULTS

Sensitization prevalences of 39 cosmetic contact allergens were tabulated. Thirty of these allergens yielded >0.3% positive reactions and are therefore included in our proposed European cosmetic series. Six were considered no longer relevant and therefore excluded. Three were included in a supplementary European cosmetic series. An additional nine allergens were included in either the core or supplemental European cosmetic series following literature review.

CONCLUSION

We have derived a potential European cosmetic series based upon the above methods. This will require ongoing investigation based upon the changing exposure profiles of cosmetic allergens as well as new and evolving substances.

Patch testing with purified and oxidized citronellol

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.

Limonene Hydroperoxides

Limonene is a fragrance widely used in cosmetics and household products. Until recently, contact allergy to limonene was considered rare because positive patch tests to it were infrequently observed. In recent years, however, it has been demonstrated that exposure of limonene to oxygen (air) results in the formation of a number of oxidation products, of which the hydroperoxides have a far stronger sensitizing potency than the pure compound. By routine testing of patients suspected of contact dermatitis with hydroperoxides of limonene, high frequencies of positive reactions were found, indicating that these chemicals are important fragrance allergens. It should be realized, however, that a number of "positive" reactions may well be false-positive, irritant responses.

Fragrant and sticky allergens from the pinewood: Cohabiting and coreacting

BACKGROUND

Tree moss (Pseudevernia furfuracea [L.] Zopf.), a lichen growing on conifers, is a frequent fragrance sensitizer. Previous studies have shown two subgroups of tree moss-allergic patients: a group sensitized to common allergens of tree and oak moss (Evernia prunastri), and another group sensitized to colophonium-derived allergens, which may contaminate tree moss extract.

OBJECTIVES

To report the results of including tree moss extract in the baseline series and discuss the clinical implications.

METHODS

Tree moss extract was included in the baseline series and sensitized patients were assessed for concomitant allergy to colophonium and oak moss, and the relevance of these reactions was analyzed.

RESULTS

Altogether, 22 of 632 patients (3.5%) had positive reactions to tree moss. Eight patients were sensitized to tree moss only (among fragrance allergens) and 75% had relevant reactions to colophonium. Fourteen patients were sensitized to other fragrance allergens as well and 28.5% had relevant colophonium reactions.

CONCLUSIONS

The prevalence of positive tree moss reactions is high enough to justify its inclusion in the baseline series. If tree moss is not included, patients with positive colophonium reactions should be informed of possible (false) cross-reactivity to tree moss to avoid this labeled fragrance allergen.

Linalool Hydroperoxides

Linalool is a fragrance widely used in cosmetics and household products. Until recently, contact allergy to linalool was considered rare because positive patch tests to it were infrequently observed. In recent years, however, it has been demonstrated that exposure of linalool to oxygen (air) results in formation of a number of oxidation products, of which the hydroperoxides have a far stronger sensitizing potency than the pure compound. By routine testing of patients suspected of having contact dermatitis with hydroperoxides of linalool, high frequencies of positive reactions were found, indicating these chemicals are important fragrance allergens. It should be realized, however, that a number of "positive" reactions may well be false-positive, irritant responses.

Molecular docking predictions of fragrance binding to human leukocyte antigen molecules

BACKGROUND

Over 4000 small chemicals have been identified as allergens capable of inducing skin sensitization. Many sensitizers are hypothesized to act as haptens producing novel antigens, which can be presented to T cells by human leukocyte antigens (HLAs). Recent studies suggest that some chemical allergens use hapten-independent mechanisms.

OBJECTIVE

To determine whether molecular docking can identify HLA molecules that bind skin-sensitizing chemical allergens.

METHODS

Structural models of HLA molecules were used as the basis for molecular docking of 22 chemical allergens. Allergens predicted to bind HLA-B*57:01 were tested for their ability to stimulate T cells by the use of proliferation and interferon-gamma enzyme-linked immunospot assays.

RESULTS

Chemical allergens that did not satisfy the criteria for hapten activity in vitro were predicted to bind more strongly to common HLA isoforms than those with known hapten activity. HLA-B*57:01, which is an HLA allele required for drug hypersensitivity reactions, was predicted to bind several allergens, including benzyl benzoate, benzyl cinnamate, and benzyl salicylate. In in vitro T cell stimulation assays, benzyl salicylate and benzyl cinnamate were found to stimulate T cell responses from HLA-B*57:01 carriers.

CONCLUSIONS

These data suggest that small-molecule skin sensitizers have the potential to interact with HLA, and show that T cell-based in vitro assays may be used to evaluate the immunogenicity of skin-sensitizing chemicals.

European Surveillance System on Contact Allergies (ESSCA): Contact allergies in relation to body sites in patients with allergic contact dermatitis

Background

Analyses of the European Surveillance System on Contact Allergies (ESSCA) database have focused primarily on the prevalence of contact allergies to the European baseline series, both overall and in subgroups of patients. However, affected body sites have hitherto not been addressed.

Objective

To determine the prevalence of contact allergies for distinct body sites in patients with allergic contact dermatitis (ACD).

Methods

Analysis of data collected by the ESSCA (www.essca‐dc.org) in consecutively patch tested patients, from 2009 to 2014, in eight European countries was performed. Cases were selected on the basis of the presence of minimally one positive patch test reaction to the baseline series, and a final diagnosis of ACD attributed to only one body site.

Results

Six thousand two hundred and fifty‐five cases were analysed. The head and hand were the most common single sites that ACD was attributed to. Differences between countries were seen for several body sites. Nickel, fragrance mix I, cobalt and methylchloroisothiazolinone/methylisothiazolinone were the most frequent allergens reported for various body sites.

Conclusions

Distinct allergen patterns per body site were observed. However, contact allergies were probably not always relevant for the dermatitis that patients presented with. The possibility of linking positive patch test reactions to relevance, along with affected body sites, should be a useful addition to patch test documentation systems.

Contact sensitization to hydroperoxides of limonene and linalool: Results of consecutive patch testing and clinical relevance

Background

Hydroperoxides of limonene and linalool are potent sensitizers.

Objectives

To investigate the prevalence of contact allergy to both hydroperoxides of limonene and hydroperoxides of linalool, to report clinical relevance, and to investigate patient demographics.

Methods

A total of 821 patients (35.6% male, mean age 42.4 years ± 17.8 years) were consecutively patch tested with our departmental baseline series and our fragrance series, including hydroperoxides of limonene 0.3% pet. and hydroperoxides of linalool 1.0% pet. The clinical relevance was assessed for all positive reactions.

Results

Positive patch test reactions to hydroperoxides of limonene and to hydroperoxides of linalool were observed in 77 patients (9.4%, 95% confidence interval [CI]: 7.4%‐11.4%) and in 96 patients (11.7%, 95%CI: 9.5%‐13.9%), respectively; 38 of these patients (4.6%, 95%CI: 3.2%‐6.0%) reacted to both. Most reactions were considered to be possibly or probably clinically relevant (66.3% and 68.8%, respectively), and a small proportion were deemed to be of certain clinical relevance (18.2% and 19.8%, respectively).

Conclusion

As compared with previous studies, high numbers of positive reactions to both hydroperoxides of limonene and hydroperoxides of linalool were observed, the majority of which were clinically relevant, supporting their inclusion in the European baseline series.

Contact Allergy: A Review of Current Problems from a Clinical Perspective

Contact allergy is common, affecting 27% of the general population in Europe. Original publications, including case reports, published since 2016 (inclusive) were identified with the aim of collating a full review of current problems in the field. To this end, a literature search employing methods of systematic reviewing was performed in the Medline^® and Web of Science™ databases on 28 January 2018, using the search terms (“contact sensitization” or “contact allergy”). Of 446 non-duplicate publications identified by above search, 147 were excluded based on scrutiny of title, abstract and key words. Of the remaining 299 examined in full text, 291 were deemed appropriate for inclusion, and main findings were summarised in topic sections. In conclusion, diverse sources of exposures to chemicals of widely-differing types and structures, continue to induce sensitisation in man and may result in allergic contact dermatitis. Many of the chemicals are “evergreen” but others are “newcomers”. Vigilance and proper investigation (patch testing) are required to detect and inform of the presence of these haptens to which our populations remain exposed.

Can the epoxides of cinnamyl alcohol and cinnamal show new cases of contact allergy?

BACKGROUND

Cinnamyl alcohol is considered to be a prohapten and prehapten with cinnamal as the main metabolite. However, many individuals who are allergic to cinnamyl alcohol do not react to cinnamal. Sensitizing epoxides of cinnamyl alcohol and cinnamal have been identified as metabolites and autoxidation products of cinnamyl alcohol.

OBJECTIVE

To investigate the clinical relevance of contact allergy to epoxycinnamyl alcohol and epoxycinnamal.

METHODS

Irritative effects of the epoxides were investigated in 12 dermatitis patients. Epoxycinnamyl alcohol and epoxycinnamal were patch tested in 393 and 390 consecutive patients, respectively. In parallel, cinnamyl alcohol and cinnamal were patch tested in 607 and 616 patients, respectively.

RESULTS

Both epoxides were irritants, but no more positive reactions were detected than when testing was performed with cinnamyl alcohol and cinnamal. Late allergic reactions to epoxycinnamyl alcohol were observed. In general, patients with late reactions showed doubtful or positive reactions to cinnamal and fragrance mix I at regular patch testing.

CONCLUSION

The investigated epoxides are not important haptens in contact allergy to cinnamon fragrance. The high frequency of fragrance allergy among patients included in the irritancy study showed the difficulty of suspecting fragrance allergy on the basis of history; patch testing broadly with fragrance compounds is therefore important.

A proposal to create an extension to the European baseline series

BACKGROUND

The current European baseline series consists of 30 allergens, and was last updated in 2015.

OBJECTIVES

To use data from the European Surveillance System on Contact Allergies (ESSCA) to propose an extension to the European baseline series in response to changes in environmental exposures.

METHODS

Data from departmental and national extensions to the baseline series, together with some temporary additions from departments contributing to the ESSCA, were collated during 2013-2014.

RESULTS

In total, 31689 patients were patch tested in 46 European departments. Many departments and national groups already consider the current European baseline series to be a suboptimal screen, and use their own extensions to it. The haptens tested are heterogeneous, although there are some consistent themes. Potential haptens to include in an extension to the European baseline series comprise sodium metabisulfite, formaldehyde-releasing preservatives, additional markers of fragrance allergy, propolis, Compositae mix, and 2-hydroxyethyl methacrylate.

CONCLUSION

In combination with other published work from the ESSCA, changes to the current European baseline series are proposed for discussion. As well as addition of the allergens listed above, it is suggested that primin and clioquinol should be deleted from the series, owing to reduced environmental exposure.

Fragrance contact allergens in 5588 cosmetic products identified through a novel smartphone application

BACKGROUND

More than 25% of the adult European population suffers from contact allergy, with fragrance substances recognized as one of the main causes. Since 2005, 26 fragrance contact allergens have been mandatory to label in cosmetic products within the EU if present at 10 ppm or above in leave-on and 100 ppm or above in wash-off cosmetics.

OBJECTIVE

To examine exposure, based on ingredient labelling, to the 26 fragrances in a sample of 5588 fragranced cosmetic products.

METHODS

The investigated products were identified through a novel, non-profit smartphone application (app), designed to provide information to consumers about chemical substances in cosmetic products. Products registered through the app between December 2015 and October 2016 were label checked according to International Nomenclature of Cosmetic Ingredients (INCI) for the presence of the 26 fragrance substances or the wording 'fragrance/parfum/aroma'.

RESULTS

The largest product categories investigated were 'cream, lotion and oil' (n = 1192), 'shampoo and conditioner' (n = 968) and 'deodorants' (n = 632). Among cosmetic products labelled to contain at least one of the 26 fragrances, 85.5% and 73.9% contained at least two and at least three of the 26 fragrances, respectively. Linalool (49.5%) and limonene (48.5%) were labelled most often among all investigated products. Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC/Lyral^® ) was found in 13.5% of deodorants. Six of the 26 fragrance substances were labelled on less than one per cent of all products, including the natural extracts Evernia furfuracea (tree moss) and Evernia prunastri (oak moss). A total of 329 (5.9%) products had one or more of the 26 fragrance substances labelled but did not have 'parfum/fragrance/aroma' listed on the label.

CONCLUSIONS

Consumers are widely exposed to, often multiple, well-established fragrance contact allergens through various cosmetic products intended for daily use. Several fragrance substances that are common causes of contact allergy were rarely labelled in this large sample of cosmetic products.