Hydroxyisohexyl 3-cyclohexene carboxaldehyde- known as Lyral®: quantitative aspects and risk assessment of an important fragrance allergen

Microbial Colonization, Biofilm Formation, and Malodour of Washing Machine Surfaces and Fabrics and the Evolution of Detergents in Response to Consumer Demands and Environmental Concerns

Bacterial attachment and biofilm formation are associated with the contamination and fouling at several locations in a washing machine, which is a particularly complex environment made from a range of metal, polymer, and rubber components. Microorganisms also adhere to different types of clothing fibres during the laundering process as well as a range of sweat, skin particles, and other components. This can result in fouling of both washing machine surfaces and clothes and the production of malodours. This review gives an introduction into washing machine use and surfaces and discusses how biofilm production confers survival properties to the microorganisms. Microbial growth on washing machines and textiles is also discussed, as is their potential to produce volatiles. Changes in consumer attitudes with an emphasis on laundering and an overview regarding changes that have occurred in laundry habits are reviewed. Since it has been suggested that such changes have increased the risk of microorganisms surviving the laundering process, an understanding of the interactions of the microorganisms with the surface components alongside the production of sustainable detergents to meet consumer demands are needed to enhance the efficacy of new antimicrobial cleaning agents in these complex and dynamic environments.

Chronic Hand Eczema

Chronic hand eczema (CHE) is a complex, challenging, and frequently multifactorial skin disease of the hands. It is very common in the general population, especially in certain professions. When hand eczema (HE) persists for longer than 3 months or has a minimum of two relapses per year after initial manifestation with complete clearance, it is considered chronic. In this case, health-related quality of life and the patient's working life are often impaired. CHE can be considered as an umbrella term because it covers different clinical pictures and etiologies. To date, there is no definite and unique HE classification. Treatment starts with identifying the individual HE etiology paralleled by symptomatic therapy (local and/or systemic and/or ultraviolet phototherapy). Sustainable management of HE requires the identification and avoidance of its triggering factors, from the professional and private environment. This includes ruling out allergic contact dermatitis if any HE persists for more than 3 months despite adequate therapy. Randomized controlled trials investigating the efficacy in HE are lacking for several treatment modalities. Patient education measures of skin protection and prevention complete the multimodal treatment.

Quantitative risk assessments of skin sensitization for 26 allergens in different consumer products in the Saudi market

Fragrance chemicals are ubiquitous in cosmetics; however, they have been linked to allergic contact dermatitis. Allergy prevention involves two main strategies. Firstly, consumers are protected by limiting the maximum concentration of fragrance in a given product to avoid inducing allergies. Secondly, consumers who are already sensitized are protected by having the presence of such fragrance communicated to them. In this study, a validated GC-MS method was employed to quantify 26 allergens in 108 products marketed in Saudi Arabia.Additionally, a quantitative risk assessment (QRA) was performed on the studied cosmetics to determine the risk of inducing allergies. The results indicated that most allergens were present at acceptable concentrations, while 19 products carried a risk of inducing allergies. Furthermore, Lilial and Lyral, two prohibited fragrances, were detected in 97 products. It should be emphasized that this is the first study conducted in Saudi Arabia to evaluate the safety of the well-known 26 fragrance allergens. Hence, this study can potentially serve as a regional standard for future research.

S2k-Leitlinie Diagnostik, Prävention und Therapie des Handekzems: S2k guideline diagnosis, prevention and therapy of hand eczema

Die S2k‐Leitlinie „Diagnostik, Prävention und Therapie des Handekzems (HE)“ gibt auf der Grundlage eines evidenz‐ und konsensbasierten Ansatzes konkrete Handlungsanweisungen und Empfehlungen für die Diagnostik, Prävention und Therapie des HE. Die Leitlinie wurde auf der Grundlage der deutschen Leitlinie „Management von Handekzemen“ aus dem Jahr 2009 und der aktuellen Leitlinie der European Society of Contact Dermatitis (ESCD) „Guidelines for diagnosis, prevention and treatment of hand eczema“ aus dem Jahr 2022 erstellt. Allgemeines Ziel der Leitlinie ist es, Dermatologen und Allergologen in der Praxis und Klinik eine akzeptierte, evidenzbasierte Entscheidungshilfe für die Auswahl sowie Durchführung einer geeigneten und suffizienten Therapie für Patienten mit Handekzemen zur Verfügung zu stellen. Die Leitlinie basiert auf zwei Cochrane‐Reviews zu therapeutischen und präventiven Interventionen beim HE. Die übrigen Kapitel wurden überwiegend basierend auf nicht systematischen Literaturrecherchen durch die Expertengruppe erarbeitet und konsentiert. Die Expertenkommission bestand aus Mitgliedern von allergologischen und berufsdermatologischen Fachgesellschaften und Arbeitsgruppen, einer Patientenvertretung und Methodikern. Im Rahmen einer Konsensuskonferenz am 15.09.2022 wurden die Vorschläge für die Empfehlungen und Kernaussagen unter Verwendung eines nominalen Gruppenprozesses konsentiert. Der strukturierte Konsensfindungsprozess wurde professionell moderiert. Die vorliegende Leitlinie hat eine Gültigkeit bis zum 22.02.2028.

S2k guideline diagnosis, prevention, and therapy of hand eczema

The consensus-based guideline "Diagnosis, prevention, and treatment of hand eczema (HE)" provides concrete instructions and recommendations for diagnosis, prevention, and therapy of HE based on an evidence- and consensus-based approach. The guideline was created based on the German guideline "Management von Handekzemen" from 2009 and the current guideline of the European Society of Contact Dermatitis (ESCD) "Guidelines for diagnosis, prevention, and treatment of hand eczema" from 2022. The general goal of the guideline is to provide dermatologists and allergologists in practice and clinics with an accepted, evidence-based decision-making tool for selecting and conducting suitable and sufficient therapy for patients with hand eczema. The guideline is based on two Cochrane reviews of therapeutic and preventive interventions for HE. The remaining chapters were mainly developed and consented based on non-systematic literature research by the expert group. The expert group consisted of members of allergological and occupational dermatological professional associations and working groups, a patient representative, and methodologists. The proposals for recommendations and key statements were consented by using a nominal group process during a consensus conference on September 15, 2022. The structured consensus-building process was professionally moderated. This guideline is valid until February 22, 2028.

Contact allergy to hydroxyisohexyl 3-cyclohexene carboxaldehyde in Italy: Prevalence, trend, and concordance with fragrance mix II

BACKGROUND

Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC), contained in fragrance mix II (FM II), has been recognized as a contact sensitizer since the mid-1990s. After several attempts to reduce its use during the last two decades, HICC was permanently banned from the European market in August 2021.

OBJECTIVES

To assess the prevalence and the time trend of contact allergy to HICC and to investigate the concordance of HICC allergy compared to FM II allergy in an unselected Italian patch test population.

METHODS/PATIENTS

Retrospective analysis on demographics and patch test results of HICC-sensitized and/or FM II-sensitized patients was performed over a 6-year period (2016-2021) at 6 patch test Clinics in Italy.

RESULTS

Among 7266 patients (4942 females, 68.0%, mean age 45.4 ± 20.6 years), 1% (70) resulted positive to HICC and 2.1% (153) to FM II. Clinical relevance was documented in 72.9% (51/70) of HICC positive patients. Among the 169 HICC and/or FM II positive patients, 9.5% had a positive reaction to HICC only, 31.9% to both HICC and FM II, and 58.6% to FM II only. The prevalence trend line of HICC positive reactions showed a decrease from 1.15% (2016) to 0.96% (2021).

CONCLUSIONS

We documented a decreasing trend of HICC allergy in Italy, in line with the data recently reported in literature. Nevertheless, HICC should be maintained in the baseline series to monitor the benefits of its ban from the European market.

Epicutaneous Patch Testing in Type IV Allergy Diagnostics: State of the Art and Best Practice Recommendations

This chapter summarises all relevant aspects of patch testing, closely following recommendations outlined in a recent European, and a German S3 guideline on diagnostic patch testing with contact allergens and medicinal products (drugs). Patch testing is indicated in patients suspected of suffering, or having been suffering, from delayed-type hypersensitivity leading to allergic contact dermatitis or other skin and mucosal diseases. Sections of this chapter include detailed indications, reasons for possibly postponing the test, considerations on choosing haptens (contact allergens) to test, various aspects of the application of patch test allergen preparations (storage, dosing) and of testing with individual materials provided by the patients. Special aspects of patch testing in cutaneous adverse drug reactions, children, or occupational contact dermatitis are outlined. Supplemental test methods, notably the repeated open application test, are briefly described. Finally, the final evaluation in terms of assessment of clinical relevance of reactions and patient counselling are outlined.

Validation of questionnaire algorithm based on repeated open application testing with the constituents of fragrance mix II: the EDEN Fragrance Study

BACKGROUND

In a European study on contact allergy in the general population, it has been hypothesized that the combination of contact allergy to a fragrance together with a history indicating dermatitis at exposure and thereafter subsequent avoidance of scented products implied a diagnosis of allergic contact dermatitis.

OBJECTIVES

The primary aim of this study was to validate this hypothesis/algorithm. The secondary aim was to investigate whether there was any association between the outcome of the recent repeated open application test (ROAT) and the patch test reactivity.

METHODS

One hundred nine subjects with and without contact allergy to fragrance mix II (FM II) were recruited. Volunteers from six European dermatology clinics participated in the study including a patch test and a ROAT.

RESULTS

Twenty-four positive ROAT reactions were noted in total including 20 of those 32 with contact allergy to FM II. None of the volunteers reacted to the vehicle (P < 0.001). More individuals with a positive algorithm had positive ROATs when compared with those with a negative algorithm. However, the difference was not statistically significant (P = 0.12). The lower the patch test concentration eliciting a positive test reaction, the more likely was a positive ROAT and the more likely that the positive ROAT appeared early during the investigative period.

CONCLUSIONS

The algorithm used in this study was not validated but it was indicated in this ROAT setup. The stronger the patch test reactivity the more likely was a positive ROAT and the more likely it was that the positive ROAT appeared early during the application period.

Computerized screening of G-protein coupled receptors to identify and characterize olfactory receptors

Olfactory receptors (ORs) are a group of G protein coupled receptors (GPCRs) that initiate chemical odorant signals. Although ORs are predominantly located in nasal epithelia to detect smell, these receptors are also present in peripherally in non-nasal organs/tissues. Since the quality of life and cognitive and sensorial features of sense of smell are worsened in multiple chemical sensitivity due to the interaction of ORs with offending compounds, it is important to not only differentiate these receptors from other GPCRs but also characterize these organelles to understand the underlying mechanisms of smelling disorders. The aim of this study was develop computerized programs to differentiate ORs from GPCRs. The computer program was developed on the basis of widely accepted basic algorithms. It is noteworthy that an accuracy of 95.5% was attained, a level not achieved using other established techniques for screening of ORs from GPCRs. The high accuracy rate indicates that this method of differential identification appears reliable. Our findings indicate that this novel method may be considered as a tool for identification and characterization of receptors which might aid in therapeutic approaches to human chemical-mediated sensitization.

Simulative structure and binding sites of lyral with olfactory receptor 10J5 using computational prediction methods

Olfactory receptor (OR) genes are extensively distributed throughout the human organism. Although these receptors are predominantly located in the olfactory epithelium, binding between odorant chemicals and corresponding ORs initiates downstream events in other tissues. In particular, exposure to allergen fragrances results in the induction of contact dermatitis. At present, current methodologies are limited in their ability to predict the consequences of fragrancy chemicals on humans. The aim of this study was designed to simulate the bindingstructure between lyral and OR10J5, a known allergen which produces contact dermatitis, and its corresponding OR OR10J5 in an effort to predict dermal outcomes using computational methods. Results demonstrated that binding between lyral and OR10J5 involved amino acid residues Phe104, Val105, Cyx178, Ile180, and Tyr258, respectively, which were located on binding sites of the receptor transmembrane 3(TM3), TM3, extracellular loop 2(EL2), EL2, TM6. Evidence indicates that computer simulating binding interactions occurred between an odorant chemical and its receptors which initiated downstream alterations accounting possibly for the observed in vivo contact dermatitis.

Contact dermatitis: a practice parameter-update 2015

This parameter was developed by the Joint Task Force on Practice Parameters, which represents the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Contact Dermatitis: A Practice Parameter-Update 2015." This is a complete and comprehensive document at the current time. The medical environment is changing and not all recommendations will be appropriate or applicable to all patients. Because this document incorporated the efforts of many participants, no single individual, including members serving on the Joint Task Force, are authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information or interpretation of this practice parameter by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by the pharmaceutical industry in drug development or promotion. Previously published practice parameters of the Joint Task Force on Practice Parameters for Allergy & Immunology are available at http://www.JCAAI.org or http://www.allergyparameters.org.

European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice

The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact dermatitis or other delayed-type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance.

Contact allergy induced by bisphenol A diglycidyl ether leachables from aluminium tubes for pharmaceutical use

BACKGROUND

Aluminium tubes for pharmaceutical use are internally lacquered with epoxy resins (ER) based on bisphenol A diglycidyl ether (BADGE). Recently, it was shown that remnants of ER polymerization like BADGE are extractable from epoxy-based coatings of commercially available tubes and may leach into semi-solid drug preparations. We aimed to evaluate the safety of BADGE-contaminated macrogol ointments in individuals sensitized to ER based on BADGE by use tests.

METHODS

Repeated open application testing (ROAT) in 11 patients sensitized to ER based on BADGE with BADGE in macrogol ointments (3 mg/kg; 30 mg/kg, equivalent to BADGE concentration determined in macrogol ointment after storage in a commercially available tube; 300 mg/kg).

RESULTS

The 30 mg/kg BADGE ointment elicited reactions in three patients, and another three patients reacted to 300 mg/kg BADGE ointment. No reactions to the vehicle control and 3 mg/kg BADGE were observed.

CONCLUSIONS

Elevated BADGE concentrations in ER-coated aluminium tubes pose a risk of developing contact dermatitis to patients sensitized to ER based on BADGE. Quality standards are deemed necessary for the production of ER-coated aluminium tubes intended for pharmaceutical use and should consider the results of the present ROAT study.

Air-oxidized linalool elicits eczema in allergic patients - a repeated open application test study

BACKGROUND

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.

OBJECTIVE

To identify threshold concentrations for elicitation of allergic contact dermatitis caused by oxidized linalool in allergic individuals with repeated exposures.

METHODS

Repeated open application tests were performed in 6 participants previously diagnosed with contact allergy to oxidized linalool. Creams containing 3.0%, 1.0% and 0.30% oxidized linalool (corresponding to 0.56%, 0.19% and 0.056% linalool hydroperoxides, respectively) and 'fine fragrance' containing 1.0%, 0.30% and 0.10% oxidized linalool (corresponding to 0.19%, 0.056% and 0.019% linalool hydroperoxides, respectively) were used twice daily for up to 3 weeks. Patch testing with a dilution series of oxidized linalool was performed.

RESULTS

Five of 6 participants reacted to the cream containing 3% oxidized linalool. With 1% oxidized linalool, a reaction was seen in 3 (cream) and 4 (fine fragrance) participants, respectively. With 0.3% oxidized linalool, 2 (cream) and 1 (fine fragrance) participants reacted.

CONCLUSION

Repeated exposure to low concentrations of oxidized linalool can elicit allergic contact dermatitis in previously sensitized individuals.

Patch testing with fragrance mix II: results of the IVDK 2005-2008

BACKGROUND

The fragrance mix (FM I), established in 1977, detects the majority, but not all cases of contact allergy to fragrances. Based on European research 2002/2003, fragrance mix II (FM II) was developed to supplement FM I. In 2005, the German Contact Dermatitis Research Group (DKG) added FM II to their baseline series.

OBJECTIVES

To evaluate reactions to FM II and its constituents in routine patch testing.

METHODS

Retrospective data analysis of the Information Network of Departments of Dermatology (IVDK), 2005-2008, of patch test results with FM II and its constituents.

RESULTS

A total of 35 633 patients were patch tested with FM II as part of the DKG baseline series. Of these, 1742 (4.9%) reacted positively. Concomitant reactions to FM I were observed in 41.9% of the patients reacting to FM II. In 367 FM II-positive patients, a full breakdown test of the mix was performed. Of these, 47.7% reacted to hydroxyisohexyl 3-cyclohexene carboxaldehyde, 16.1% to citral, 11.4% to farnesol, 3.8% to hexyl cinnamal, 2.7% to coumarin, and 2.5% to citronellol.

CONCLUSIONS

FM II is an important screening and diagnostic tool to detect fragrance allergy. Hydroxyisohexyl 3-cyclohexene carboxaldehyde is the most important fragrance allergen in FM II.

The dose-response relationship between the patch test and ROAT and the potential use for regulatory purposes

BACKGROUND

Allergic contact dermatitis is common and can be prevented. The relationship between thresholds for patch tests and the repeated open application test (ROAT) is unclear. It would be desirable if patch test and ROAT data from already sensitized individuals could be used in prevention.

OBJECTIVES

The aim was to develop an equation that could predict the response to an allergen in a ROAT based on the dose-response curve derived by patch testing.

MATERIALS/METHODS

Results from two human experimental elicitation studies with non-volatile allergens, nickel and the preservative methyldibromo glutaronitrile (MDBGN), were analysed by logistic dose-response statistics. The relation for volatile compounds was investigated using the results from experiments with the fragrance chemicals hydroxyisohexyl 3-cyclohexene carboxaldehyde and isoeugenol.

RESULTS

For non-volatile compounds, the outcome of a ROAT can be estimated from the patch test by: ED(xx)(ROAT) = 0.0296 ED(xx)(patch test). For volatile compounds, the equation predicts that the response in the ROAT is more severe than the patch test response, but it overestimates the response.

CONCLUSIONS

This equation may be used for non-volatile compounds other than nickel and MDBGN, after further validation. The relationship between the patch test and the ROAT can be used for prevention, to set safe levels of allergen exposure based on patch test data.

Dose-Response Relationships and Threshold Levels in Skin and Respiratory Allergy

A literature study was performed to evaluate dose-response relationships and no-effect levels for sensitization and elicitation in skin- and respiratory allergy. With respect to the skin, dose-response relationships and no-effect levels were found for both intradermal and topical induction, as well as for intradermal and topical elicitation of allergenic responses in epidemiological, clinical, and animal studies. Skin damage or irritation may result in a significant reduction of the no-effect level for a specific compound. With respect to the respiratory tract, dose-response relationships and no-effect levels for induction were found in several human as well as animal studies. Although dose-response relationships for elicitation were found in some epidemiological studies, concentration-response relationships were present only in a limited number of animal studies. Reported results suggest that especially relatively high peak concentrations can induce sensitization, and that prevention of such concentrations will prevent workers from developing respiratory allergy. Moreover, induction of skin sensitization may result in subsequent heightened respiratory responsiveness following inhalation exposure. The threshold concentration for the elicitation of allergic airway reactions in sensitized subjects is generally lower than the threshold to induce sensitization. Therefore, it is important to consider the low threshold levels for elicitation for recommendation of health-based occupational exposure limits, and to avoid high peak concentrations. Notwithstanding the observation of dose-response relationships and no-effect levels, due to a number of uncertainties, no definite conclusions can be drawn about absolute threshold values for allergens with respect to sensitization of and elicitation reactions in the skin and respiratory tract. Most predictive tests are generally meant to detect the potential of a chemical to induce skin and/or respiratory allergy at relatively high doses. Consequently, these tests do not provide information of dose-response relationships at lower doses such as found in, for example, occupational situations. In addition, the observed dose-response relationships and threshold values have been obtained by a wide variety of test methods using different techniques, such as intradermal exposure versus topical or inhalation exposure at the workplace, or using different endpoints, which all appear important for the outcome of the test. Therefore, especially with regard to respiratory allergy, standardized and validated dose-response test methods are urgently required in order to be able to recommend safe exposure levels for allergens at the workplace.

Frequency of and trends in fragrance allergy over a 15-year period

BACKGROUND

The widespread use of fragrance-containing products is probably the most important reason for its high impact in allergic contact dermatitis.

OBJECTIVES

To describe the frequency of contact allergy to fragrance allergens as tested in the standard series, in relation to age, sex and lesion locations. To determine trends in frequency over the years and to study the association between positive tests observed with the different fragrance-allergy markers as well as between specific fragrance allergens and locations of the lesions.

PATIENTS/METHODS

10 128 patients underwent patch testing between January 1990 and December 2005 at the Dermatology department in Leuven.

RESULTS

1463 (14.5%), that is, 380 (26%) males and 1083 (74%) females, reacted positively to at least 1 fragrance-allergy marker in the standard series: 9% to fragrance mix I, 6% to Myroxylon pereirae, and 4.8% to colophonium (often in association), 2.1% to hydroxyisohexyl 3-cyclohexene carboxaldehyde and 2.1% to fragrance mix II, the latter 2 allergens having been introduced more recently. Over the years, fragrance contact allergy has shown a fluctuating trend. Hands and face were the most commonly affected body sites. Moreover, a significant association was found between specific fragrance allergens and certain locations.

CONCLUSIONS

This study illustrates that fragrance contact allergy is common in patients suffering from contact dermatitis.

The relationships between exposure dose and response in induction and elicitation of contact hypersensitivity in humans

Like all physiological systems, the human immune system exhibits dose-response relationships in its reactions. The strength of sensitization is related to the potency of the immunogen and the dose that reaches the immune system. In skin, as sensitizing dose per unit area (mug cm(-2)) is increased on a log scale, there is a sigmoid dose-response curve for subsequent reactivity. Similarly, the response to elicitation shows a classical sigmoid response to increasing challenge dose, with the dose per unit area again being the determinant. There is a clear inverse correlation between the strength of sensitization and the subsequent dose of antigen to which an individual will respond. This is reflected in the different challenge systems used to diagnose the existence of allergic contact sensitization to a given allergen. The occluded patch test aims to use the highest concentration possible to detect the weakest degrees of allergy, whereas the repeated open application test uses much lower concentrations similar to those encountered in real life, applied repeatedly but without occlusion, to assess clinical relevance. Many authors have attempted to use the lowest concentrations to which rare, highly sensitized individuals can react to define the concentrations which might be free of risk in terms of inducing allergic sensitization. However, it is clear that the dose-response relationships for induction of sensitivity by repeated low-dose exposures must be carefully defined in future studies. This article reviews the dose-response relationships of human contact sensitization.

Nickel allergy: relationship between patch test and repeated open application test thresholds

BACKGROUND

The frequency of nickel allergy varies between different population groups. Exposure regulation has proven effective in decreasing the frequency. Experimental studies with other allergens have shown a significant relation between patch test reactivity and repeated open application test (ROAT) reactivity.

OBJECTIVES

This study was aimed at determining the elicitation threshold in nickel-allergic individuals in a patch test and a ROAT, and comparing the threshold from these two test methods.

METHODS

Twenty nickel-allergic persons were tested with a dilution series of 19 concentrations in a patch test and a dilution series of three concentrations in a ROAT, with duration of up to 21 days. Eighteen persons with no nickel allergy were included as control group for the ROAT.

RESULTS

The predicted dose which will elicit a reaction in 10% of allergic individuals was calculated to be 0.78 microg nickel cm(-2) in the patch test. The threshold for the ROAT (in microg nickel cm(-2) per application) was significantly lower than the threshold for the patch test, while the dose-response for the accumulated ROAT dose at 1 week, 2 weeks and 3 weeks was very similar to the patch test dose-response; indeed, there was no statistically significant difference.

CONCLUSIONS

For elicitation of nickel allergy the elicitation threshold for the patch test is higher than the elicitation threshold (per application) for the ROAT, but is approximately the same as the accumulated elicitation threshold for the ROAT. This may be important for risk assessment based on dose-response results from allergic patients.

Patch test results with patients' own perfumes, deodorants and shaving lotions: results of the IVDK 1998-2002

OBJECTIVE

Assessment of the value of patch testing patients' own perfumes, eau de toilette, deodorants and shaving lotions with regard to diagnosing contact allergy to fragrances, and an analysis of the spectrum of concurrent patch test reactions to single fragrance allergens.

STUDY DESIGN

Data of the Information Network of Departments of Dermatology (IVDK; http://www.ivdk.org) regarding patch test results with above products brought in by the patient, considered as possible cause of contact dermatitis, were retrospectively analysed. Between 1998 and 2002, 1468 patients were patch tested with 2557 single products (deodorants, n = 1094; eau de toilette, n = 598; perfume, n = 530; and pre- or after-shave, n = 325; remainder not classifiable), mostly 'as is'.

RESULTS

Positive reactions were observed in 129 patients (to 191 products). In 58 of these patients, no further patch test reactions to the fragrance mix (FM-I), Myroxylon pereirae resin (balsam of Peru) or 4-(4-hydroxy-4-methyl-pentyl)-3-cyclohexencarboxaldehyde (e.g. Lyral(R)) were found. A strong association between contact sensitivity to the above commercial allergens and positive reactions to products was observed. Some single compounds such as ylang-ylang oil, propolis and especially oak moss absolute are important allergens in the 'perfume-positive' subgroup, but less in a subgroup positive to own deodorants.

DISCUSSION

Patch testing this scope of products, brought in by the patient, can be regarded as a simple, safe and effective method to diagnose clinically relevant contact sensitization - the more so, as the composition of such products is ever-changing, and the sensitivity of established 'screening allergens' is thus insufficient.

Sensitization to 26 fragrances to be labelled according to current European regulation

To study the frequency of sensitization to 26 fragrances to be labelled according to current European regulation. During 4 periods of 6 months, from 1 January 2003 to 31 December 2004, 26 fragrances were patch tested additionally to the standard series in a total of 21 325 patients; the number of patients tested with each of the fragrances ranged from 1658 to 4238. Hydroxymethylpentylcyclohexene carboxaldehyde (HMPCC) was tested throughout all periods. The following frequencies of sensitization (rates in %, standardized for sex and age) were observed: tree moss (2.4%), HMPCC (2.3), oak moss (2.0), hydroxycitronellal (1.3), isoeugenol (1.1), cinnamic aldehyde (1.0), farnesol (0.9), cinnamic alcohol (0.6), citral (0.6), citronellol (0.5), geraniol (0.4), eugenol (0.4), coumarin (0.4), lilial (0.3), amyl-cinnamic alcohol (0.3), benzyl cinnamate (0.3), benzyl alcohol (0.3), linalool (0.2), methylheptin carbonate (0.2), amyl-cinnamic aldehyde (0.1), hexyl-cinnamic aldehyde (0.1), limonene (0.1), benzyl salicylate (0.1), gamma-methylionon (0.1), benzyl benzoate (0.0), anisyl alcohol (0.0). 1) Substances with higher sensitization frequencies were characterized by a considerable number of '++/+++' reactions. 2) Substances with low sensitization frequencies were characterized by a high number of doubtful/irritant and a low number of stronger (++/+++) reactions. 3) There are obviously fragrances among the 26 which are, with regard to contact allergy, of great, others of minor, and some of no importance at all.

Experimental elicitation with hydroxyisohexyl-3-cyclohexene carboxaldehyde-containing deodorants

Hydroxyisohexyl-3-cyclohexene carboxaldehyde (HICC) known as Lyral is a frequent allergen. It is used in more than 50% of marketed deodorants. The aim of the present study was to determine elicitation thresholds for HICC under simulated conditions of deodorant use. 15 patients with previously diagnosed contact allergy to HICC were patch tested with 5 solutions of HICC-scented and HICC-unscented deodorants. Patients and 10 healthy controls performed a use test in the axillae using deodorants scented with HICC in increasing concentrations and unscented deodorants as control. The concentration of HICC was increased every second week (200, 600, and 1800 p.p.m.) until either a reaction developed or for 6 weeks. 14 patients completed the study, and all developed unilateral eczema from the HICC-containing deodorant, while controls were all negative (P= 0.004). In 9/14 patients, a positive use test developed during the first 2 weeks to the deodorant containing 200 p.p.m. HICC. Positive correlations were found between the day of positive use and patch test threshold concentration of the HICC solutions (r= 0.71, P= 0.01) as well as the patch test thresholds of the HICC-scented deodorants (r= 0.74, P= 0.007). In conclusion, HICC elicits allergic contact dermatitis in a high proportion of sensitized individuals at common usage concentrations in deodorants.

Sensibilización al Lyral®

INTRODUCTION

Lyral is a fragrance that is present in many cosmetic products. It has turned into an emergent allergen during the last years. In studies carried out in other European countries, the prevalence of sensitization to Lyral has been found to be 1.9-2.7 %, but it is unknown the prevalence in Spain, as well as the need to include it or not in the standard series of the Spanish Group of Contact Dermatitis (GEIDC).

METHODS

We have patch-tested to Lyral all patients with suspicion of contact dermatitis of any origin who attended our Service between April and May-2005.

RESULTS

From a total of 170 patients included in our study, 2 of them had a sensitization to Lyral (1.2 %). One of these two patients had an axillae contact dermatitis caused by a deodorant containing Lyral. The other patient was a masseur-woman with a contact dermatitis on both hands, with periods of dissemination to upper extremities and trunk, and who used several cosmetics products for private reasons and during her job.

CONCLUSION

Although the sample of this study is quite small, we think that the results allow to suspect that Lyral is one of the main allergens, or even the most important, in causing allergic contact dermatitis to fragrances in our environment. Therefore, we believe that we must raise the inclusion of Lyral in the standard series of GEIDC, either as independent allergen, or including it in a new mixture of fragrances.

Fragrance allergy: assessing the risk from washed fabrics

The prevalence of contact allergy to fragrance ingredients increased during the last part of the 20th century with the consequence that a substantial number of individuals are at risk of experiencing allergic contact dermatitis (ACD) if they have a sufficient degree of skin exposure to the chemical to which they have become sensitized. Such exposure does not necessarily have to arise from the type of source that originally induced the sensitization. A number of sources of exposure are clearly associated with risk of elicitation of ACD, but the role of fragrance deposited on fabrics, for example as a result of laundry processes, also can be questioned. In this article, firstly, the risk of the induction of fragrance-related ACD from exposure to fragrance via fabric is considered. Using a quantitative risk-assessment approach, the risk appears to be extremely low. The possibility that fragrance residues on laundered fabrics might elicit reactions in those already sensitized by a different route is also discussed. Clinically, clothing pattern dermatitis associated with fragrance allergy is almost never observed, although this could be investigated clinically by exposing sensitized individuals to the relevant fragrance allergen.