Search

Background: The use of methylisothiazolinone (MI) as a preservative in cosmetic products caused an alarming increase in MI contact allergy across Europe in the 2010s. This was followed by regulations of use with a total ban on leave-on (implemented in 2017) and reduced use concentrations in rinse-off cosmetics (2018)., Objective: To follow-up on the prevalence of contact allergy to MI and the related benzisothiazolinone (BIT) and octylisothiazolinone (OIT) in consecutively patch-tested patients in Europe., Methods: A cross-sectional audit following the design of two previous audits on MI contact allergy from 1 May 2022 to 31 October 2022 included all patients patch tested with the European baseline series, including or supplemented with MI, BIT and OIT across 10 departments in eight European countries., Results: A total of 2554 patients were consecutively patch tested with the three isothiazolinones during the study period. The prevalence of MI and BIT contact allergy was 2.9% (95% confidence interval [CI]: 2.3%-3.7%; range 1.1%-5.8%) and 3.1% (95% CI: 2.4%-3.9%; range 0.0%-6.6%), respectively; that of OIT was 0.7% (95% CI: 0.4%-1.1%; range 0%-3.2%). Rinse-off cosmetic (73.3%) and leave-on cosmetic products (13.3%) were still associated with eliciting allergic contact dermatitis to MI., Conclusion: We confirmed a positive impact of regulatory measures on the prevalence of MI contact allergy in Europe, which halved compared to 2015. However, our data suggest that consumers may still be exposed to older cosmetic products containing MI. BIT has superseded MI in causing contact allergy, despite not being allowed for use in cosmetic products., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Patch testing is the reference standard for the diagnosis of allergic contact dermatitis. Identification and avoidance of culprit allergens are essential in the treatment of this disease. Each year, new allergens are identified as emerging or important. The authors discuss allergens that are common, enduring, emergent, incompletely recognized, and controversial for the practicing allergist and dermatologist. This Clinical Management Review will encompass a review of fragrances, preservatives, rubber, acrylates, metals, and medications; their common sources of exposure; controversies in diagnosis and patch testing; management and how to avoid those allergens. This review will also include practical aspects of diagnosis and management and will provide resources that can be used as guidance for physicians and patients on nickel, methylchloroisothiazolinone/methylisothiazolinone, and fragrance, the most common allergens positive on patch testing., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Fragrance substances are a frequent cause of contact allergy worldwide. Fragrance exposure varies by sex, age and possibly country, influenced by cosmetic availability, environmental conditions and cultural practices., Objectives: To systematically review and gather prevalence of sensitization to fragrance mix I (FM I) and fragrance mix II (FM II) in consecutively patch tested European dermatitis patients., Method: A total of 4134 publications on patch test results of European dermatitis patients, published from 1981 to 2022, were systematically reviewed according to a previously registered and published PROSPERO protocol., Results: Eighty-four eligible original articles were analysed. Overall prevalence of sensitization to fragrance mix I (FM I) was 6.81% (95% CI: 6.37-7.28), and FM II was 3.64% (95% CI: 3.3-4.01). Sensitization to FM I was most prevalent in Central and Eastern Europe and to FM II in Western Europe. No clear time trends were observed. Among paediatric dermatitis patients, sensitization prevalence for FM I and FM II was 4.09% (95% CI: 3.37-4.96) and 2.17% (95% CI: 1.53-3.07)., Conclusion: The frequency of positive patch test results for both FMI and FMII remains high. Sensitization is also prevalent among children. Enhanced regulation and labelling of cosmetic products play a vital role in averting exposure and sensitization to fragrance allergens., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Patch testing is the only clinically applicable diagnostic method for Type IV allergy. The availability of Type IV patch test (PT) allergens in Europe, however, is currently scarce. This severely compromises adequate diagnostics of contact allergy, leading to serious consequences for the affected patients. Against this background, the European Society of Contact Dermatitis (ESCD) has created a task force (TF) (i) to explore the current availability of PT substances in different member states, (ii) to highlight some of the unique characteristics of Type IV vs. other allergens and (iii) to suggest ways forward to promote and ensure availability of high-quality patch testing substances for the diagnosis of Type IV allergies throughout Europe. The suggestions of the TF on how to improve the availability of PT allergens are supported by the ESCD, the European Academy of Allergy and Clinical Immunology, and the European Academy of Dermatology and Venereology and intend to provide potential means to resolve the present medical crisis., (© 2024 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Quantitative risk assessment (QRA) for skin sensitization is used to derive safe use levels of sensitising fragrance ingredients in products. Post-marketing surveillance of the prevalence of contact allergy to these ingredients provides relevant data to help evaluate the performance of these measures., Objectives: To determine a suitable patch test concentration for five fragrance materials that had hitherto not been tested on a regular basis. These concentrations are then to be used in a surveillance study with patch testing consecutive patients over an extended monitoring period., Materials and Methods: Furaneol, CAS.3658-77-3; trans-2-hexenal, CAS.6728-26-3; 4,8-dimethyl-4,9-decadienal, CAS.71077-31-1; longifolene, CAS.475-20-7; benzaldehyde, CAS.10052-7, were patch tested with other fragrance allergens in four clinics. Patch testing was conducted in three rounds, starting with the lowest concentrations of the five ingredients. The doses were increased in the subsequent rounds if no late-appearing positive reactions and virtually no irritant reactions were reported., Results: Overall, 373 patients were tested. No positive allergic reaction was reported to the five ingredients. Patch test results of other fragrance allergens are reported., Conclusions: The highest test concentrations are each considered safe for patch testing consecutive patients. Further surveillance based on these preparations will evaluate the hypothesis that QRA-driven consumer product levels of these fragrances can prevent sensitization., (© 2024 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: The contact allergy prevalences in patch-tested patients are usually higher than those in the population, owing to morbidity-driven selection., Objectives: To examine the differences between two samples, one from the population, one from the patch test clinic, in one area of Germany (Jena, Thuringia)., Methods: Between August 2008 and October 2011, a total of 519 participants of the population-based european dermato-epidemiology network (EDEN) fragrance study were patch tested in Jena using a TRUE Test baseline series extended with some pet.-based (fragrance) allergen preparations. Between 2007 and 2012 (inclusive), 1906 routine patients were patch tested for suspected allergic contact dermatitis (ACD) in the Jena University Hospital Department; of these 1694 (83.2%) with the German baseline series using pet./aq.-based, investigator-loaded allergens., Results: In the population (clinical) sample, 19.6% (41.1%) were sensitized to at least one of the allergens considered. The most common baseline series allergens in the population/clinical sample were nickel (10.5%/13.2%), fragrance mix (FM) II (2.9%/6.7%), FM I (2.3%/8.3%), and cobalt (1.6%/5%). The clinical sample was slightly older (71.5% vs 55.9% age 40+) and included less males (36% vs 49.3%)., Conclusions: Results are quite similar, although prevalences are usually higher in the clinical setting, with the exception of p-tert-butylphenol formaldehyde resin., (© 2021 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) has been the most reported fragrance chemical for two decades and will be prohibited in cosmetic products from August 2021., Objectives: To describe the time trend of HICC contact allergy in European patients with dermatitis in 2009 to 2019, and the added value of testing HICC separately in the baseline series., Methods: Data were reviewed for 124 472 patients with dermatitis who were patch tested with HICC 5% pet. in the baseline series in the European Surveillance System on Contact Allergy (ESSCA) network (2009 to 2018) and at the Herlev-Gentofte Hospital Department of Dermatology and Allergy (2009 to 2019)., Results: Contact allergy to HICC was found in 1.98% of 9865 patients in Gentofte and 1.62% of 114 607 patients in the ESSCA network. Overall, the prevalence decreased annually, with 0.156 percentage points (P = .001) in Gentofte and 0.051 percentage points (P = .0002) in ESSCA. The frequency of missed contact allergy to HICC when testing only with fragrance mix II (FMII) was 0.17% (17/9865) and 0.35% (405/114607) of the whole test population in the Gentofte and ESSCA populations, respectively., Conclusions: This is the first study to demonstrate a significant decline in HICC allergy in European patients with dermatitis, most likely attributed to the upcoming European ban., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2020 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

Background: Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq., Objectives: To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS., Materials and Methods: A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs., Results: A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] -0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance., Conclusions: Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen., (© 2020 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

Background: Clinical surveillance of the prevalence of contact allergy in consecutively patch tested patients is a proven instrument to continually assess the importance of contact allergens (haptens) assembled in a baseline series., Objectives: To present current results from the European Surveillance System on Contact Allergies, including 13 countries represented by 1 to 11 departments., Methods: Anonymized or pseudonymized patch test and clinical data from various data capture systems used locally or nationally as transferred to the Erlangen data centre were pooled and descriptively analysed after quality control., Results: In the 4 years (2015-2018), data from 51 914 patients patch tested with the European baseline series (EBS) of contact allergens were analysed. Contact allergy to nickel was most frequent (17.6% positive), followed by contact allergy to fragrance mix I (6.9%), methylisothiazolinone (MI; 6.2%), and Myroxylon pereirae resin (balsam of Peru; 5.8%)., Conclusions: While the prevalence of MI contact allergy decreased substantially following regulatory intervention, the persistently high levels of allergy to metals, fragrances, other preservatives, and rubber chemicals point to problems needing further research and, potentially, preventive efforts. Results with national additions to the baseline series provide important information on substances possibly to be considered for inclusion in the EBS., (© 2020 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Contact sensitization is a common condition. The spectrum of the most important allergens may change over the course of time owing to changes in exposure. Using the so-called baseline series, a collection of the most important and frequent allergens, both population-related and clinical epidemiological studies have been performed., Objectives: Basic epidemiological concepts and special aspects regarding the epidemiology of contact allergies are presented., Materials and Methods: A concise adaptation of textbook knowledge and a selective literature search were performed., Results: On the population level, about 25% of people are sensitized to at least one substance included in the baseline series, by far most often to nickel. In view of a prevalence of around 4%, fragrances are important contact allergens, too, along with preservatives. Among patients patch tested for suspected allergic contact dermatitis, the ranking of the most important allergen groups is similar, but the prevalences are (much) higher., Conclusions: Short-term changes in exposure and subsequently in the spectrum of major contact allergens can best be illustrated by clinical surveillance based on routinely collected data and, if needed, preventive measures can be initiated. In addition to time trend analyses, subgroup analyses may offer important clues regarding the identification of sensitizing and eliciting exposures, respectively.

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens., (© 2019 The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.)

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens. Note: This publication is part 1 of the short version of the S3 guidelines for "Epicutaneous patch testing using contact allergens and drugs" (registry no. 013 - 018; date: March 20, 2019; valid until December 31, 2021). Part 2 of the short version will be published in the next issue. The long version of these guidelines can be accessed at www.awmf.org. The method report is available as online publication (https://www.awmf.org/leitlinien/detail/ll/013-018.html) and contains the evidence tables in its appendix., (© 2019 The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.)

Background: Assessment of the clinical relevance of patch test reactions is an essential part of the diagnostic work-up of patients with (occupational) contact dermatitis. However, final diagnostic information, particularly the clinical relevance of allergic patch test reactions, has hitherto been ill-represented in clinical documentation systems (patch test software) and surveillance registries based on these., Objectives: To develop, implement as a pilot study, and analyse concerning feasibility and contents a new concept of representing the full scope of diagnostic information utilized in the diagnosis of patients with (occupational) contact dermatitis., Methods: On the basis of a European working group discussion on items to document and catalogue lists to use for this purpose, an online documentation system to collect data was set up, followed by pilot use involving 9 dermatology departments across Europe., Results: Data on 176 patients with suspected occupational hand dermatitis were included; among these, work-relatedness was confirmed in 150, and in 53 non-occupational aetiology was the sole or a contributory cause. Data were further analysed with regard to occupations, product categories, substances (haptens), source of information on which the evaluation was based, and various combinations of these factors, to illustrate the usefulness of the proposed data representation., Conclusions: An improved method of data collection is presented that more accurately links allergen to exposure and to clinical disease and patient history, and thus better represents clinical relevance. This enables more precise analysis of the causation of contact dermatitis, occupational or non-occupational, and thereby better targeting of prevention. The development of future databases should incorporate the above considerations to record the results of investigation., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Methylisothiazolinone (MI) caused an epidemic of contact allergy in Europe, as shown by data from many countries, but no studies from Croatia exist. Also, data are lacking on the severity of allergic contact dermatitis (ACD) caused by MI, and its impact on quality of life and prognosis., Objectives: To determine the frequency of MI contact allergy among Croatian dermatitis patients, identify causative exposures, assess the impact of disease, and study the prognosis., Methods: Data were collected for consecutive dermatitis patients with MI contact allergy patch tested in Croatia between November 2, 2015 and November 3, 2016., Results: MI contact allergy was diagnosed in 13.2% of 798 tested patients. The most frequent dermatitis locations were the hands (76%) and face (61%). In 89.3% of patients, MI contact allergy was found to be of current relevance. Considerable severity and impact on daily life of disease was found at the first consultation, but this significantly decreased until follow-up 3 months later., Conclusions: Patch testing is the standard method for the diagnosis of ACD, and it has been shown to have an important beneficial effect on prognosis. The severity of MI ACD and the impact on daily life emphasize the need for prevention., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Polysensitization, defined as being allergic to three or more haptens from the European baseline series, is considered to reflect increased susceptibility to developing a contact allergy, and is likely to be associated with an impaired quality of life., Objectives: To evaluate the prevalences of polysensitization across Europe and to analyse factors associated with polysensitization., Methods: Patch test data collected by the European Surveillance System on Contact Allergies (ESSCA; www.essca-dc.org) in consecutively patch tested patients from January 2009 to December 2014, comprising 11 countries and 57 departments, were retrospectively analysed., Results: A total of 86 416 patients were available for analysis, showing a standardized prevalence of polysensitization of 7.02%, ranging from 12.7% (Austria) to 4.6% (Italy). Allergen pairs with the strongest association are reported for the total population, for South Europe, and for North/Central Europe. Overall, polysensitized patients showed a higher percentage of extreme (+++) positive patch test reactions than oligosensitized patients. Female sex, occupational dermatitis and age > 40 years were risk factors for polysensitization., Conclusions: The varying prevalences of polysensitization across Europe most likely reflect differences in patient characteristics and referral patterns between departments. Known risk factors for polysensitization are confirmed in a European dermatitis population., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Synthetic fragrances and natural essential oils (EOs) are used in perfumery and found in various cosmetics. Essential oils are also increasingly used to promote wellness. In previous studies, the sensitization potential of some EOs has been identified; however, the current prevalence of sensitivity is largely unknown., Objectives: The aim of this study was to determine frequency of positive patch-test reactions to EOs tested in the baseline series, along with 3 fragrance markers (FMs) (fragrance mix I, fragrance mix II, and Myroxylon pereirae), in consecutive patients in the US/Canadian North American Contact Dermatitis Group (NACDG) (2009-2014) and the central European, trinational Information Network of Departments of Dermatology (IVDK) (2010-2014)., Methods: This study used a retrospective analysis of patch-test results and relevant demographic/clinical data collected electronically by the networks, obtained with Santalum album 10% petrolatum (pet) (IVDK only); Cananga odorata 2% (NACDG) and 10% (IVDK) pet; Jasminum species 2% (NACDG) and 5% (IVDK) pet; Mentha piperita 2% pet; Melaleuca alternifolia, oxidized (tea tree oil), 5% pet; and Lavandula angustifolia 2% pet (latter 3 NACDG only)., Results: Overall, 62,354 patients were tested to 3 FMs and EOs (NACDG, 13,398; IVDK, 48,956); 11,568 (18.6%) reacted to at least 1 FM or EO, whereas 857 (1.4%) reacted to 1 or more EOs but none of the 3 FMs. For both the NACDG and IVDK populations, individuals who were positive to 1 or more of the 9 study allergens were significantly less likely to be male, have occupational skin disease, or have hand involvement and significantly more likely to have leg dermatitis and be 40 years and older (P's ≤ 0.005). Prevalence rates for EOs were as follows: S. album, 1.4% IVDK; C. odorata, 1.1% NACDG and 2.4% IVDK; Jasminum species, 0.7% NACDG and 1.4% IVDK; M. piperita, 0.9% NACDG; L. angustifolia, 0.3% NACDG; and M. alternifolia, 0.3% NACDG. Of the 140 NACDG patients who reacted to 1 or more of the 5 NACDG EOs but none of the FMs, M. alternifolia yielded most positive reactions (45%); half of these reactions were strong (++ or +++, 50.8%) and of definite/probable clinical relevance (52.4%). Of the 717 IVDK patients who reacted to 1 or more of the 3 IVDK EOs but none of the 3 FMs, 38% were positive to C. odorata, 38% to S. album and 36% to Jasminum species.', Conclusions: Testing to EOs may be important for detecting sensitivity not detected by FMs alone. In North America, M. alternifolia is an important and clinically relevant sensitizer often not detected by FM. In Europe, as well as in North America, clinical relevance is often difficult to evaluate because (1) labeling of EOs when used as fragrance is not mandatory, and (2) these mixtures may indicate sensitization to 1 or more of their individual constituents from other sources, including synthetic fragrances.

Background: Rubber additives constitute an important group of contact allergens, particularly in certain occupations., Objectives: To collect information regarding the current practice of using a 'rubber series' in Europe, and discuss this against the background of evidence concerning the prevalence of allergy in order to derive a recommendation for a 'European rubber series'., Methods: The following were performed: (i) a survey targeting all members of the COST action 'StanDerm' consortium, (ii) analysis of rubber contact allergy data in the database of the European Surveillance System on Contact Allergies, and (iii) a literature review., Results: Information from 13 countries was available, from one or several departments of dermatology, and occasionally occupational health. Apart from some substances tested only in single departments, a broad overlap regarding important allergens was evident, but considerable variation existed between departments., Conclusions: An up-to-date 'European rubber series' is recommended, with the exclusion of substances only of historical concern. A 'supplementary rubber series' containing allergens of less proven importance, requiring further analysis, is recommended for departments specializing in occupational contact allergy. These should be continually updated as new evidence emerges., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Contact allergy to rubber additives is common, particularly in patients with occupational dermatitis., Objectives: To descriptively analyse and compare patch test reactions in patients patch tested both with the baseline series and with an additional 'rubber series' as used in the department., Methods: Patch test data from those members of the European Surveillance System on Contact Allergies (ESSCA) network (www.essca-dc.org) who also contributed data on rubber series patch test results were retrospectively analysed., Results: Among 29 522 patients patch tested, 2870 were eligible, that is, patch tested both with the baseline series and with a special rubber series. Of these, 8.8% had positive reaction(s) to one of the baseline screening rubber allergens (as compared with 4.2% in all patients), most often to carba mix, 12.3% had positive reaction(s) to allergens from an additional rubber series, and 6.4% had positive reaction(s) to both., Conclusions: Additional testing with a dedicated rubber series, containing break-down single ingredients of mixes from the baseline series and additional rubber allergens, is warranted in patients with suspected contact allergy to rubber, to avoid false-negative results., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The reporting of scientific results (in the field of contact dermatitis/allergy) should include a description of the methods used, including, but not limited to, standardized patch testing. Several aspects always need to be reported, such as duration of exposure, reading times, vehicle, and concentration of allergens. However, concerning other aspects, explicit compliance with international patch testing guidelines, notably the European Society of Contact Dermatitis guideline, which covers all relevant general aspects, is deemed to be a sufficient description of methods, supplemented by study-specific information, including partial non-compliance with the guideline, as indicated. Besides technical aspects, the quality of reporting of scientific results has several other dimensions, including epidemiological and biostatistical aspects discussed in this article. Prospectively, when a study is planned, performed, and reported, issues such as selection of patients and sample size and their impact on power and precision, the role of misclassification and potential conflicts of interests need to be addressed and discussed, respectively. Retrospectively, when a study is read and analysed, all relevant aspects of quality should be considered when the weight of evidence that a study publication provides is evaluated. Employing rigid 'quality criteria' may have the detrimental effect of relevant, if slightly imperfect, evidence being deliberately excluded., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Fragrance mix I (FM I) and its single constituents contain 5% and 1% sorbitan sesquioleate (SSO), respectively. SSO is a rare sensitizer and a potential irritant., Objectives: To determine whether the outcome of the FM I breakdown test is affected by positive patch test reactivity to SSO., Methods: A retrospective analysis of data from the Information Network of Departments of Dermatology, 1998-2013, was performed., Results: The full FM I breakdown test including SSO was tested in 2952 patients. Of these, 154 (5.2%) had a positive patch test reaction to SSO 20% pet. and 2709 (91.8%) had a negative patch test reaction. Positive reactions to one or more of the single fragrances contained in the mix were significantly more common (82.5% versus 57.3%) in SSO-positive patients, who also had more multiple reactions than FM I-positive patients with negative SSO reactions (61.5% versus 21.3% patients with reactions to two or more fragrances)., Conclusions: Our results indicate that reactivity to SSO markedly affects the outcome of patch testing with FM I and its single constituents. SSO must be an obligatory part of the full FM I breakdown test, and should ideally be included in the baseline series., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Contact allergy to fragrances is common, and impairs quality of life, particularly in young women., Objective: To provide current results on the prevalences of sensitization to fragrance allergens used as markers in the baseline series of most European countries., Methods: Data of patients consecutively patch tested between 2009 and 2012 in 12 European countries with fragrance allergens contained in the baseline series were collected by the European Surveillance System on Contact Allergies network and descriptively analysed. Four departments used the TRUE Test(®) system., Results: The 'basic markers' were tested on 51 477 [fragrance mix II (FM II)] to 57 123 [Myroxylon pereirae, balsam of Peru] patients, and yielded positive reactions as follows: fragrance mix I 6.9%, Myroxylon pereirae 5.4%, FM II 3.8%, colophonium 2.6%, and hydroxyisohexyl 3-cyclohexene carboxaldehyde 1.7%, with some regional differences. Prevalences with TRUE Test(®) allergens were lower. Additional fragrances were tested on 3643 (trimethylbenzenepropanol) to 14 071 (oil of turpentine) patients, and yielded between 2.6% (Cananga odorata) and 0.7% (trimethylbenzenepropanol) positive reactions., Conclusions: Contact allergy to fragrances is common throughout Europe, with regional variation probably being explained by patch test technique, and differences in exposure and referral patterns. The current basic markers of fragrance sensitivity in the baseline series should be supplemented with additional fragrance allergens., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Patch test results often vary between departments, and also between countries. Such variation may be partly attributable to systematic effects introduced by patient characteristics, differing exposures, patient selection, or methodological differences., Objective: To examine the amount of variation of patient characteristics in terms of the MOAHLFA index and of the proportion of patients with at least one positive reaction to the (European) baseline series ('P' measure), and to examine potential reasons for the variation., Methods: A retrospective analysis was performed of patch test data from 63 530 consultations collected by 53 departments from 12 countries participating in the European Surveillance System on Contact Allergies (ESSCA) ( www.essca-dc.org) between 2009 and 2012., Results: Considerable variation in the prevalence of the MOAHLFA factors between departments was found, caused, for example, by differing specializations (e.g. occupational dermatology) or patient characteristics. Notable variation concerning the 'P' measure was observed; however, larger national networks (contributing to the ESSCA) tend to have quite similar ranges of this measure., Conclusions: Data from one department per country give valuable insights into the spectrum of contact allergy prevalence rates in that country, but are not as representative as national data pooled from several departments., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Many key ingredients of hair cosmetics (in particular, dyes, bleaches, and hair-styling agents) are potent (strong to extreme) contact allergens. Some heterogeneity is apparent from published results concerning the range of allergens for which patch testing is important. The objective of the present review was to collect information on the current practice of using 'hair cosmetic series', and discuss this against the background of evidence concerning consumer/professional exposure and regulatory aspects to finally derive a recommendation for a 'European hair cosmetic series'. The methods involved (i) a survey targeting all members of the COST action 'StanDerm' (TD1206) consortium, (ii) analysis of data in the database of the European Surveillance System on Contact Allergies (ESSCA), and (iii) literature review. Information from 19 European countries was available, partly from national networks, and partly from one or several departments of dermatology or, occasionally, occupational medicine. Apart from some substances being tested only in single departments, a broad overlap regarding 'important' allergens was evident. Some of the substances are no longer permitted for use in cosmetics (Annex II of the Cosmetics Regulation). An up-to-date 'European hair cosmetics series', as recommended in the present article, should (i) include broadly used and/or potent contact allergens, (ii) eliminate substances of only historical concern, and (iii) be continually updated as new evidence emerges., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Contact sensitization in children is more frequent than previously thought., Methods: The ESSCA collected patch test data from 11 European countries aggregated to 4 European regions., Results: Six thousand and eight patients aged 1-16 years old with suspected allergic contact dermatitis were analyzed during a period of 8 years (2002-2010). The overall prevalence of at least one positive reaction to a hapten was 36.9%. The 10 most frequent haptens were as follows: nickel sulfate, cobalt chloride and potassium dichromate, neomycin sulfate, Myroxylon pereirae resin (balsam of Peru), para-phenylenediamine, chloromethylisothiazolinone/methylisothiazolinone 3:1, fragrance mix, lanolin alcohols, and colophony. No difference was found in the prevalence of at least one positive reaction to at least one hapten between boys and girls and between children with atopic dermatitis and children without. Children without atopic dermatitis, when compared with those with, had a significantly higher prevalence of contact sensitization for nickel sulfate (20.91% vs 16.87%, respectively), 4-tert. butylphenol formaldehyde resin (1.61% vs. 0.7%), and para-phenylenediamine (2.49% vs. 1.3%)., Limitations of the Study: Chamber loading is not an exact science and variation may occur between staff and departments. Interinstitution variations in readings can occur. A possible geographic confounder is that the southern regions tested more children in the younger age group. Relevance was not addressed due to difficulties in the application of a set of uniform definitions., Conclusions: Our study adds information on the most common contact allergens detected in children which could help to define a Standard European Pediatric Baseline Series., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Occupational contact dermatitis is one of the most common occupational diseases in Europe. In order to develop effective preventive measures, detailed and up-to-date data on the incidence, main causes and professions at risk of occupational contact dermatitis are needed., Objectives: To describe the pattern of patch test reactivity to allergens in the European baseline series of patients with occupational contact dermatitis in different occupations., Methods: We analysed data collected by the European Surveillance System on Contact Allergy (ESSCA) network from 2002 to 2010, from 11 European countries., Results: Allergens in the European baseline series associated with an at least doubled risk of occupational contact dermatitis include: thiuram rubber chemical accelerators, epoxy resin, and the antimicrobials methylchloroisothiazolinone/methylisothiazolinone, methyldibromo glutaronitrile, and formaldehyde. The highest risk of occupational contact dermatitis was found in occupations classified as 'other personal services workers', which includes hairdressers, nursing and other healthcare professionals, precision workers in metal and related materials, and blacksmiths, tool-makers and related trades workers., Conclusions: In the planning and implementation of measures aimed at preventing occupational contact dermatitis, the focus should be on the identified high-risk occupational groups and the most common occupational allergies., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Physical therapists frequently come in contact with materials that can potentially cause skin irritation and/or allergies. Nevertheless analyses of professionally relevant sensitization patterns are currently lacking., Patients and Methods: A descriptive analysis of the patch test results from the Information Network of Departments of Dermatology (IVDK) was carried out considering patients employed full-time as physical therapists during the years 2007-2011. Information includes dermatologic diagnoses, possible contact substances and cofactors as well as the "hit list" of the most common allergens., Results: Among the patients (n = 134) the most common diagnoses (1(st) and 2(nd) ) were allergic contact dermatitis (23.9 %), chronic irritant dermatitis (17.2 %) and atopic dermatitis (19.4 %). In 80 of the 134 patients (59.7 %), the skin lesions were located on the hands. In 62 (46.3 %) of the cases, skin disease was considered work-related. The contact with cosmetics, creams, disinfectants, topical medications and the use of gloves were relevant as putative triggering factors for the respondents. The most common allergens were nickel (II) sulfate (16.5 %), fragrance mix (12.2 %) and fragrance mix II (13.0 %)., Conclusions: In this first comprehensive study of contact allergies among physical therapists in German-speaking countries, a link between skin disease and work was felt likely in nearly 50 % of the tested cohort. To which extent the results shown in this work can be confirmed and which consequences these have for occupational preventive measures should be examined in additional, preferably longitudinal studies., (© The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.)

Background: No observed event is a special, but not uncommon, result in patch test studies. The interpretation of such findings depends critically on the sample size (n) of the investigation, and is statistically addressed by the use of confidence intervals (CIs)., Objective: To define the statistically correct method of calculating a CI with a confidence level of 1 - α, where α denotes the tolerated statistical error probability, for an observed prevalence of 0%., Methods: A literature survey and evaluation of the statistical methods was conducted. The popular statistical software packages SPSS™ and SAS™ were examined with regard to the methods implemented, and the results obtained, for estimating such CIs in this special case., Results: The evaluation identified [0; 1 - α(1/n) ], which is well approximated by [0; 3/n] for α = 0.05, as an appropriate method to compute a CI with a confidence level of 1 - α. The resulting CI is an exact one, and more efficient than standard solutions. Popular statistical software such as SPSS™ and SAS™ offers only various inefficient or even invalid procedures, but does not include this method., Conclusions: It is easy to calculate a CI for an observed prevalence of 0% obtained in some studies. Such a CI facilitates the interpretation of such a finding, as it puts the observed zero result into adequate statistical perspective., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The pattern of contact sensitization to the supposedly most important allergens assembled in the baseline series differs between countries, presumably at least partly because of exposure differences. Objectives. To describe the prevalence of contact sensitization to allergens tested in consecutive patients in the years 2007 and 2008, and to discuss possible differences., Methods: Data from the 39 departments in 11 European countries comprising the European Surveillance System on Contact Allergy network (www.essca-dc.org) in this period have been pooled and analysed according to common standards., Results: Patch test results with the European baseline series, and country-specific or department-specific additions to it, obtained in 25 181 patients, showed marked international variation. Metals and fragrances are still the most frequent allergens across Europe. Some allergens tested nationally may be useful future additions to the European baseline series, for example methylisothiazolinone, whereas a few long-term components of the European baseline series, namely primin and clioquinol, no longer warrant routine testing., Conclusions: The present analysis points to 'excess' prevalences of specific contact sensitization in some countries, although interpretation must be cautious if only few, and possibly specialized, centres are representing one country. A comparison as presented may help to target in-depth research into possible causes of 'excess' exposure, and/or consideration of methodological issues, including modifications to the baseline series., (© 2012 John Wiley & Sons A/S.)

Background: The warm und humid environment, friction and occlusion within shoes make the feet to a favorable body site to acquire allergic contact dermatitis., Objectives: To evaluate and compare patch test results in patients with suspected contact allergy of the feet with the results in those with concomitant involvement of the feet/legs, feet/hands, and all others tested (excluding secondary involvement of the feet in 'others'), with regard to specific patterns of clinical data and patch test results., Methods: For the present cross-sectional study, data were collected by the 59 participating centres of the Information Network of Departments of Dermatology in Germany, Austria, and Switzerland, including 102 209 patients patch-tested between January 2001 and December 2010., Results: Allergens that were significantly over-represented in the tested 2671 foot patients included potassium dichromate, colophonium, and p-tert-butylphenol-formaldehyde resin. Among materials brought in by the patients, shoe pieces (27.5%), topical medications/pharmaceutical products (24.4%) and cosmetics (16.8%) played a major role. The final diagnoses of vesicular and hyperkeratotic dermatitis, as well as psoriasis, were significantly more common among foot patients., Conclusions: Chromium compounds and adhesives were the most common causes of allergic contact dermatitis among our foot patients. Psoriasis should be considered, particularly when the hands are concomitantly affected., (© 2012 John Wiley & Sons A/S.)

Background: The proportion of patients with a positive patch test reaction to at least one allergen from the baseline series differs between departments., Objectives: To further define the above mentioned proportion, termed the 'P' measure, to examine factors associated with this measure, to describe its variation over time and between centres, and to discuss possible uses., Patients and Methods: Eighteen departments have been 'long-term' participants in the Information Network of Departments of Dermatology (IVDK; www.ivdk.org), that is, since 1995 (1997 in two cases). In these departments, 80 919 consultations for patch testing with the baseline series, in the composition of the series valid at that time, were documented until December 2009. Bivariate and multifactorial analyses addressed factors associated with being patch test-positive to at least one baseline series allergen., Results: Of the study population, 46.5% had at least one positive test reaction, with considerable variation being seen between centres and a general decline during the study period. Among other factors, female sex, occupational causation and a high suspicion of allergic contact dermatitis were significantly associated with having at least one positive patch test reaction to the baseline series., Conclusions: The 'P' measure should prove useful as another perspective on departmental characteristics, and should be reported along with established variables (MOAHLFA index)., (© 2011 John Wiley & Sons A/S.)

Background: According to clinical impression, extreme patch test reactions (+++) to p-phenylenediamine (PPD) are not uncommon in children., Objectives: To investigate the patch test reactivity in children (aged 1-14 years) in comparison with other age groups and other allergens., Methods: A retrospective analysis was performed of data from the German Information Network of Departments of Dermatology, including all patients consecutively patch tested between 1994 and 2004 with PPD, and, for comparison, nickel, fragrance mix I, and methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI). The distribution of +, ++ and +++ grades of positive reactions among those with a positive reaction were analysed in five age strata., Results: We found a strikingly higher proportion of +++ reactions to PPD in children than in all other age groups (p < 0.001). No such difference was observed for the other allergens. The main suspected exposures associated with extreme reactions to PPD in children were hair dyes and 'henna tattoos'., Conclusions: The high proportion of extreme patch test reactions to PPD, but not to other important allergens, in children reflects intense sensitization, probably because of a high induction dose from PPD-containing 'henna tattoos'. In children with a history of contact allergy to 'henna tattoos' or hair dyes, the standard patch test concentration of PPD 1% should be drastically reduced., (© 2011 John Wiley & Sons A/S.)

Background: The irritant properties of some preservatives and the use of water as the patch test vehicle for some of them call for a critical evaluation of patch test reactions to preservatives., Objectives: To examine the association between test vehicle (petrolatum versus water) or the patients' age and history of atopic dermatitis, respectively, and certain patterns of reaction to preservatives., Patients/methods: Data of 34,631 patients tested in 34 centres with 11 common preservatives were retrospectively analysed. The dynamic reaction patterns, reaction indices (RIs) and positivity ratios (PRs) were statistically evaluated., Results: All preservatives yielded more crescendo reactions in older than in younger patients. For 10 of 11 preservatives, the percentage of crescendo reactions was slightly higher in patients without a history of atopic dermatitis, and for 10 of 11 agents the RI was higher in patients with a positive history of atopic dermatitis. No consistent vehicle-related effects on reaction characteristics were found. Chlorhexidine digluconate 0.5% in water and sodium benzoate 5% in petrolatum had the lowest RIs, highest PRs, and lowest proportions of crescendo reactions., Conclusions: Water as a vehicle is unlikely to affect the reaction patterns of preservatives. The generally used patch test preparations of chlorhexidine digluconate and sodium benzoate need improvement., (© 2010 John Wiley & Sons A/S.)

Background: Essential oils are used in perfumery and in products for aromatherapy or balneotherapy. Previous studies have shown some to be important contact sensitizers. A practical diagnostic approach, based on the results of a large, central European network and other evidence, is needed., Methods: Data of the Information Network of Departments of Dermatology (IVDK; www.ivdk.org) on all patients patch tested between January 2000 and December 2008 with essential oils were retrospectively analysed., Results: 15 682 patients of 84 716 consulting in the period had been tested with at least one essential oil, and 637 reacted positively to at least one of the essential oils, most commonly to ylang-ylang oil (I and II) (3.1% as weighted mean of positive tests in special series and consecutive testing), lemongrass oil (1.8%), jasmine absolute (1.6%), sandalwood oil and clove oil (1.5% each). Cross-reactivity between distillate and main allergen, if available, was marked., Conclusions: Patch testing the important essential oils should be considered in patients with a suggestive history. Additionally, culprit products brought in by the patient should be tested, closing a diagnostic gap by (i) including those other essential oils not included in the commercial test series and (ii) providing a means of testing with the oxidized substances to which the patient had actually been exposed., (© 2010 John Wiley & Sons A/S.)

Background: Contact sensitization to fragrances is common both in clinical and in population samples. The spectrum of allergens is broad and diverse, and to some extent covered by a set of screening agents., Objectives: To examine the current frequency of contact sensitization to fragrance allergens in patients routinely patch tested for suspected allergic contact dermatitis with the baseline series and special series., Patients and Methods: Between 2005 and 2008, 40 709 patients were patch tested in the departments of the Information Network of Departments of Dermatology (http://www.ivdk.org). Results with selected fragrances were analysed., Results: Of all patients tested with the German baseline series, 15.1% reacted positively to fragrance mix (FM) I (6.6% positive), FM II (4.6% positive) or Myroxylon pereirae resin (balsam of Peru, 6.8% positive). Among the single constituents of FM I, Evernia prunastri [oak moss absolute (abs.)] was the leading allergen, and amyl cinnamal the least frequent allergen. Among fragrances not included in FM I or FM II, Evernia furfuracea (tree moss abs.) was the most common allergen., Conclusions: For diagnostic purposes, it is necessary to combine several screening agents. The frequency of contact sensitization differs greatly between single fragrances., (© 2010 John Wiley & Sons A/S.)

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., (© 2010 John Wiley & Sons A/S.)

Background: While the use of methyldibromo glutaronitrile (MDBGN) in leave-on products is clearly associated with high sensitization or elicitation risk, such a clear-cut relation could be questioned with regard to rinse-off products., Objective: The objective of this study was to find a maximum non-eliciting concentration for rinse-off products in MDBGN patch test-positive patients., Patients and Methods: We performed a use-related test [repeated open application test (ROAT)] in patients sensitized to MDBGN with a liquid soap containing three concentrations of MDBGN (50, 200, and 400 p.p.m. MDBGN, respectively). The soap at 50 p.p.m. was used twice daily for 4 weeks. If no reaction of the skin was observed, the product with the next higher concentration was used for another 4 weeks, etc., Results: In total, 32/37 evaluated cases [86.5%; lower exact one-sided 95% confidence limit (CL): 73.7%] did not react to any of the preparations. The remaining reacted as follows: 1/37 reacted to 50 p.p.m., 3/37 to 200 p.p.m., and 1/37 to 400 p.p.m. The cumulative non-response to 50 p.p.m. was 97.3% (lower CL: 87.8%)., Conclusions: The majority of subjects sensitized to MDBGN-tolerated rinse-off products containing a maximum concentration of 400 p.p.m. A concentration in rinse-off products in the range of 50 p.p.m. could be regarded as safe for most individuals already sensitized. These concentrations will presumably prevent induction (sensitization) also.

Background: Patch testing with benzoyl peroxide 1% pet. frequently leads to (weak) positive reactions, often with uncertain clinical relevance., Objectives: To describe the pattern of patch tests reactions to benzoyl peroxide and to identify patients at risk of a positive reaction., Methods: Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 1992-2007., Results: Benzoyl peroxide 1% pet. was tested in 29 758 patients. Weak positive reactions (erythema, infiltration, possibly papules) occurred in 6.5%, and strong positive reactions (erythema, infiltration, vesicles) in 1.3%. According to logistic regression analysis, strong positive reactions to benzoyl peroxide were associated with leg or face dermatitis, work as dental technicians, young age and being female. Patients with atopic dermatitis had a significantly increased risk of weak positive reactions only., Conclusions: Our analysis confirms that benzoyl peroxide 1% pet. is a problematic patch test preparation. Hence, clinical relevance of reactions to benzoyl peroxide has to be assessed very carefully. Patients with atopic dermatitis are particularly prone to irritant reactions to benzoyl peroxide. True allergic reactions may occur in dental technicians and following the treatment of leg ulcers with highly concentrated benzoyl peroxide in past. In contrast, widely used acne treatments with benzoyl peroxide seems to sensitize only rarely.

Objective: To identify the concentration of the fragrance compound hydroxyisohexyl 3-cyclohexene carboxaldehyde (INCI) (HICC) that is sufficiently low not to cause an allergic reaction in patients with proven sensitization., Methods: Repeated open application testing (ROAT) in 64 subjects with 2 preparations (perfume and cream) in different concentration (0.005-2.5%). Confirmatory patch testing with four preparations in two different concentrations (2.5% and 5%)., Results: The concentrations of HICC being tolerated by 90% of those sensitized to HICC are estimated as <88.2 ppm (cream) and <270 ppm (perfume) equivalent to 1.2 microg/cm(2) (perfume) and 4.9 microg/cm(2) (cream). Patch test preparations differed with regard to sensitivity (88.5-98.1%) and specificity (37.5-87.5%) against the ROAT result as external criterion. ROAT concentrations and the reaction strength in patch testing were inversely correlated (Kendall's tau-b: 0.69), both indicating the existence of different degrees of susceptibility., Conclusion: To protect 90% (50%) of people sensitized, the use concentration should be in the range of 0.009-0.027% (0.18-0.34%), depending on the product type. Taking into account these results, excessive concentrations should be avoided, as this would continue to sensitize people. Close monitoring is indispensable to prove the efficacy of any recommendations aiming to prevent induction.

Over the 20th century, several contact allergy epidemics arose in Western Europe. Today, industries use various assays to determine the sensitization potential of new ingredients and thereby prevent new contact allergy outbreaks. This study debates acceptable risk of sensitization in the general population by using a new epidemiological tool. The clinical epidemiology (CE) and drug utilization research (DUR) method recently estimated the 10-year contact allergy prevalence in the general population in Germany and Denmark based on patch test reading data in combination with an estimate of the number of persons eligible for patch testing each year based on patch test sales data. A reverse CE-DUR was performed to make delineations between the 10-year prevalence of contact allergy in the general population and the corresponding theoretical prevalences of contact allergy observed among patients with dermatitis in Denmark and Germany. Results indicated that if 1/100 subjects in the general population in Denmark and Germany had contact allergy; dermatologists would observe a prevalence of contact allergy among dermatitis patients was between 4.5-8.0% and 2.5-10.4%, respectively. The reverse CE-DUR approach can be used to alert public health authorities if the estimated number of sensitized persons in the general population is above a certain threshold.

Background: Contact allergy (CA) to topical corticosteroids (CS) is relatively rare; however, current data from Germany are not available. Furthermore, valid risk assessment needs to take into account of the actual exposure to CS in the population., Patients and Methods: The reaction profile of 9 CS included in a "CS test battery" of the German Contact Dermatitis Research Group (DKG) in patients seen in German clinics belonging to the Information Network of Departments of Dermatology (IVDK; http://www.ivdk.org) between 01/1995 and 12/2004 was analyzed. Applying the "Clinical Epidemiology/Drug Utilization Research" approach, annual incidences of CA to CS in Germany were extrapolated. These estimates were used as numerator for a relative incidence (RI) estimate which used exposure in terms of "defined daily doses" (DDD) to the respective CS as denominator, the latter information collected by the AOK Research Institute (WIdO)., Results: On average, 7.4% of all patients were patch tested with the CS series, mostly yielding < 1% positive reactions. Exceptions included hydrocortisone 17-butyrate (1.5%), amcinonide (1.6%) and budesonide (2.6%). With a RI of 10.7, 23.6 and 4.9 per 100,000 DDD, respectively, the three CS mentioned classify as moderate topical drug allergens. Clobetasol 17-propionate and triamcinolone acetonide both yielded a RI of 1.4/100,000 DDD, indicating low sensitization risk. For hydrocortisone, betamethasone, prednisolone and dexamethasone (RI < 1/100,000 DDD) the risk of sensitization appears minute., Conclusions: The results support and extend previous evidence on the CA risk of CS, adding to a therapeutic index and risk assessment.

Objectives: An accurate diagnosis of (occupational) contact sensitization by patch testing is a prerequisite for efficient preventive management. However, previously observed seasonal fluctuations in patch-test reactions indicate some influence of meteorological conditions. The present analysis aims at quantifying the possible impact of temperature and humidity on patch-test reactions to occupationally related allergens., Methods: Clinical data from 61 780 patients tested with standard series allergens potentially related to occupational exposure from 1993 through 2001 were collected by a contact sensitization surveillance network.The association between the patch-test results and meteorological data (air temperature and humidity) collected at the time and the approximate location of the testing was analyzed in a multinomial logistic regression analysis., Results: For three allergens (a dye and two biocides), the odds of irritant or doubtful allergic reactions increased during cold and arid conditions. Two of them (pphenylenediamine and formaldehyde) also showed an association between weak positive allergic reactions and such weather. In contrast, reactions to various adhesive, plastic, and rubber-related allergens were not associated with weather conditions., Conclusions: An overall increase in skin irritation, brought on by cold and dry conditions, may instigate an increase in positive reactions by leading doubtful allergic reactions to be (falsely) categorized as allergic for at least two of the considered allergens. For the most part, however, weather conditions were not associated with reactions to occupational allergens. Thus the validity of patch testing does not largely seem to be compromised by ambient meteorological conditions.

Background: Nickel, cobalt and chromium are some of the most common causes of type IV sensitizations and subsequent allergic contact dermatitis. Accurate diagnosis of contact sensitization to these metal salts is made possible through standardized patch testing; however, patch tests with metal allergens may be influenced by meteorological conditions at the time of testing. We aimed to investigate how patch test reactions to these metals relate to outdoor temperature and humidity at the time of testing., Methods: Clinical patch test results from 61,435 patients tested at Austrian and German dermatology departments participating in a contact sensitization surveillance network (www.ivdk.org) from 1993 through 2001 were evaluated with weather data measured near the testing location and at the time of testing. Test reactions and ambient temperature and humidity were examined with multinomial logistic regression models., Results: The odds of irritant and doubtful reactions to all 3 ionized metals increased during cold/arid conditions, and the odds of weak allergic (positive) reactions to nickel and cobalt also increased during cold/dry weather. Strong allergic reactions were essentially independent of weather conditions., Conclusions: The increase in irritant and doubtful reactions coinciding with decreasing temperature and humidity may be the result of an overall increase in skin irritation brought about by these ambient conditions. The observed increases in erythematous and infiltrated ('weak allergic') reactions may be due to doubtful reactions increasing in intensity and being (falsely) classified as positive during colder and drier conditions., (Copyright (c) 2008 S. Karger AG, Basel.)