Contact allergies to dental materials in patients.

BACKGROUND: Concerns regarding contact allergies and intolerance reactions to dental materials are widespread among patients. Development of novel dental materials and less frequent amalgam use may alter sensitization profiles in patients with possible contact allergy. OBJECTIVES: To analyse current sensitization patterns to dental materials in patients with suspected contact allergy. METHODS: This retrospective, multicentre analysis from the Information Network of Departments of Dermatology (IVDK) selected participants from 169 834 people tested in 2005-2019 and registered with (i) an affected area of 'mouth' (and 'lips'/'perioral'), (ii) with the dental material in question belonging to one of three groups (dental filling materials, oral implants or dentures or equivalents) and (iii) with patch-testing done in parallel with the German baseline series, (dental) metal series and dental technician series. RESULTS: A total of 2730 of 169 834 tested patients met the inclusion criteria. The patients were predominantly women (81.2%) aged ≥ 40 years (92.8%). The sensitization rates with confirmed allergic contact stomatitis in women (n = 444) were highest for metals (nickel 28.6%, palladium 21.4%, amalgam 10.9%), (meth)acrylates [2-hydroxyethyl methacrylate (HEMA) 4.8%] and the substances propolis (6.8%) and 'balsam of Peru' (11.4%). The most relevant acrylates were HEMA, 2-hydroxypropyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pentaerythritol triacrylate. Few men were diagnosed with allergic contact stomatitis (n = 68); sensitization rates in men were highest for propolis (14.9%) and amalgam (13.6%). CONCLUSIONS: Allergic contact stomatitis to dental materials is rare. Patch testing should not only focus on metals such as nickel, palladium, amalgam and gold, but also (meth)acrylates and the natural substances propolis and 'balsam of Peru'.

Occupational contact allergy: The European perspective-Analysis of patch test data from ESSCA between 2011 and 2020.

BACKGROUND: Occupational skin diseases have led the occupational disease statistics in Europe for many years. Especially occupational allergic contact dermatitis is associated with a poor prognosis and low healing rates leading to an enormous burden for the affected individual and for society. OBJECTIVES: To present the sensitization frequencies to the most relevant allergens of the European baseline series in patients with occupational contact dermatitis (OCD) and to compare sensitization profiles of different occupations. METHODS: The data of 16 022 patients considered having OCD after patch testing within the European Surveillance System on Contact Allergies (ESSCA) network between January 2011 and December 2020 were evaluated. Patients (n = 46 652) in whom an occupational causation was refuted served as comparison group. RESULTS: The highest percentages of OCD were found among patients working in agriculture, fishery and related workers, metal industry, chemical industry, followed by building and construction industry, health care, food and service industry. Sensitizations to rubber chemicals (thiurams, carbamates, benzothiazoles) and epoxy resins were associated with at least a doubled risk of OCD. After a decline from 2014 onwards, the risks to acquire an occupation-related sensitization to methyl(chloro)isothiazolinone (MCI/MI) and especially to methylisothiazolinone (MI) seem to increase again. Sensitization rates to formaldehyde were stable, and to methyldibromo glutaronitrile (MDBGN) slightly decreasing over time. CONCLUSIONS: Among allergens in the European Baseline Series, occupational relevance is most frequently attributed to rubber accelerators, epoxy resins and preservatives.

Occupational contact dermatitis in painters and varnishers: Data from the Information Network of Departments of Dermatology (IVDK), 2000 to 2019.

INTRODUCTION: Painters and varnishers ("painters") are exposed to various contact allergens and skin irritants, and therefore, are at risk for developing occupational dermatitis (OD). OBJECTIVE: To describe the spectrum of occupational sensitizations in painters and revise the corresponding current patch test recommendations. PATIENTS AND METHODS: Retrospective analysis of Information Network of Departments of Dermatology (IVDK) data from 2000 to 2019 with focus on male painters with OD, ages 20-59 years (n = 557) in comparison to age-matched male painters without OD (n = 422) and male OD patients who have had never worked as painters (n = 13 862). RESULTS: Male painters with OD have a significantly higher rate of allergic contact dermatitis and face dermatitis than male patients with OD who work in other professions. Positive patch tests to epoxy resin, methylisothiazolinone (MI), and methylchloroisothiazolinone (MCI)/MI were significantly more frequent in painters with OD than in the other groups. Epoxy resin sensitization was significantly associated with face dermatitis. CONCLUSIONS: Epoxy resin, MI, and MCI/MI represent the most important occupational sensitizers in painters. In addition to baseline, resins and glues, and industrial biocides series, the patients' own workplace materials should be tested in painters with suspected OD.

Improving povidone-iodine and iodine preparations for patch testing.

BACKGROUND: Allergy evaluation by patch testing with povidone-iodine (PVP-I) or iodine remains challenging, because current patch test preparations frequently lead to false-positive or irritant skin reactions. OBJECTIVES: To investigate different preparations for iodine patch tests and to assess their clinical relevance with repeated open application tests (ROATs). METHODS: We monocentrically analyzed 95 patients with suspected allergy to disinfectants in retrospect who underwent parallel iodine patch testing with four preparations: PVP-I 2% aq., 5% aq., 10% aq., and iodine 0.5% pet. RESULTS: In 27 of 95 patients (28.4%), we found positive reactions to one of the four test preparations. After ROATs in 22 of these 27 positively tested individuals, only one patient was diagnosed with iodine allergy. In contrast, 31 of 95 patients (32.6%) showed irritant or questionable patch test reactions on day 2 (D2) and/or D3 and/or D7 to one or more test preparations. Testing with PVP-I 2% aq. resulted in the lowest number of doubtful skin reactions while detecting the single allergic patient. CONCLUSION: PVP-I 2% aq. was found to be the optimal patch test preparation. In general, iodine allergy appears to be substantially overestimated, and positive patch test responses to iodine should prompt an urgent ROAT for confirmation before diagnosing iodine allergy.

Relevance of contact sensitizations in occupational dermatitis patients with special focus on patch testing of workplace materials.

BACKGROUND: Studies on patch testing with workplace materials and evaluation of current occupational relevance of positive patch test reactions are scarce in patients with occupational dermatitis (OD). OBJECTIVES: To identify frequent sensitizations with occupational relevance and to determine the value of patch testing with workplace materials in OD patients. PATIENTS AND METHODS: Results and clinical data of 654 patients with suspected OD patch tested between 2013 and 2017 were analysed. RESULTS: Occupational allergic contact dermatitis was diagnosed in 113 (17.3%) patients. Mechanics had the widest range of occupational sensitizations. Sensitization to epoxy resin was rated occupationally relevant in almost all handicraft trades. Among positive patch test reactions to workplace products, those to water-based metal working fluids and leave-on cosmetic products were most frequent. Despite frequent testing, protective gloves only rarely elicited positive reactions. Preservatives and rubber compounds were most frequently identified as currently occupationally relevant. CONCLUSIONS: Rubber allergy is occupationally relevant especially in healthcare workers and cleaners. Generally, preservatives including formaldehyde releasers are important allergens in OD patients. Leave-on cosmetic products must not be forgotten as allergen sources. Patch testing both workplace materials and standardized test preparations has a complementary value and is beneficial for the diagnostic work-up of OD patients.

Contact sensitization in dental technicians with occupational contact dermatitis. Data of the Information Network of Departments of Dermatology (IVDK) 2001-2015.

BACKGROUND: Dental technicians (DTs) are at increased risk for allergic contact sensitization. OBJECTIVES: To assess the current spectrum of occupational sensitization in DTs with occupational contact dermatitis (OCD). METHODS: A retrospective analysis of Information Network of Departments of Dermatology patch test data from the years 2001-2015 concerning DTs with OCD was performed. RESULTS: Patients of the study group (226 DTs with OCD) were significantly more often diagnosed with allergic contact dermatitis (37.6% versus 18.5%; p = 0.0002) than patients of the control group (124 DTs without OCD). In the study group, positive reactions were most frequently observed to methacrylates and/or acrylates (n = 67). Of these, 61 patients showed positive reactions to at least one of the five most frequent allergens in this group, namely 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methyl methacrylate, ethyl methacrylate, and/or ethylene glycol dimethacrylate. In contrast, no positive reactions to diurethane dimethacrylate (DUDMA) occurred. Among allergens of the German Contact Dermatitis Research Group series 'dental metals', positive reactions were less frequent and were mainly to palladium chloride (n = 6). CONCLUSIONS: The present data analysis showed that the sensitization spectrum and spectrum of cross-reactivity are largely unchanged as compared with the 1990s. It can be concluded that test recommendations are still valid and useful, except for the methacrylate DUDMA, which could be omitted.

Contact sensitization in patients with suspected textile allergy. Data of the Information Network of Departments of Dermatology (IVDK) 2007-2014.

BACKGROUND: Textile dyes, rubber, elements or textile resins carry the risk of inducing allergic contact sensitization. OBJECTIVES: To assess clinical data and patch test results for dermatitis patients with suspected textile allergy. METHODS: A retrospective analysis of Information Network of Departments of Dermatology data of the years 2007-2014 of patients patch tested because of suspected textile allergy was performed. RESULTS: Patients of the study group (n = 3207) suffered more frequently from leg, trunk and generalized dermatitis than patients of the control group (n = 95210). Among the allergens of the textile dye series, the highest frequency of positive reactions was observed for p-aminoazobenzene (5.1%) and p-phenylenediamine (PPD) (4.5%), followed by Disperse Orange 3 (3.1%), Disperse Blue 124 (2.3%), Disperse Blue 106 (2.0%), Disperse Red 17 (1.1%), and Disperse Yellow 3 (1.1%), partly with concomitant reactions. Patch testing with the patients' own textiles was performed in 315 patients, with positive reactions in 18 patients. These were mostly elicited by blue or black textiles with tight skin contact. Only 2 of these patients also reacted to textile dyes from the German Contact Dermatitis Research Group series. CONCLUSIONS: For the comprehensive diagnosis of contact sensitization in patients with suspected textile dermatitis, combined patch testing is indicated, with (i) PPD and a textile dye series and (ii) patients' own clothing.

Patch testing with rubber series in Europe: a critical review and recommendation.

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.

Sensitization to reactive diluents and hardeners in epoxy resin systems. IVDK data 2002-2011. Part II: concomitant reactions.

BACKGROUND: Beside the basic resins, reactive diluents and hardeners are important sensitizers in epoxy resin systems (ERSs). Because of chemical similarities, immunological cross-reactivity may occur. OBJECTIVES: To analyse concomitant reactivity among reactive diluents and hardeners in the patients concerned, as one integral part of a research project on the sensitizing capacity of ERSs (FP-0324). METHODS: A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2002-2011, was performed. RESULTS: There was close concomitant reactivity to 1,6-hexanediol diglycidyl ether and 1,4-butanediol diglycidyl ether (1,4-BDDGE), and to phenyl glycidyl ether (PGE) and cresyl glycidyl ether (CGE), whereas reactions to p-tert-butylphenyl glycidyl ether occurred more independently from those to PGE and CGE. Concomitant reactions to butyl glycidyl ether and 1,4-BDDGE may point to a common allergenic compound derived from the metabolism of 1,4-BDDGE. Among the structurally more diverse group of hardeners, there was no evidence of immunological cross-reactions. CONCLUSIONS: More detailed knowledge of cross-reactivity among ERS components facilitates the interpretation of patch test results and will allow safer ERSs to be composed in the future.

Sensitization to reactive diluents and hardeners in epoxy resin systems. IVDK data 2002-2011. Part I: reaction frequencies.

BACKGROUND: Epoxy resin systems (ERSs), consisting of resins, reactive diluents, and hardeners, are indispensable in many branches of industry. In order to develop less sensitizing ERS formulations, knowledge of the sensitizing properties of single components is mandatory. OBJECTIVES: To analyse the frequency of sensitization in the patients concerned, as one integral part of a research project on the sensitizing potency of epoxy resin compounds (FP-0324). METHODS: A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2002-2011, and a comparison of reaction frequencies with (surrogate) exposure data, were performed. RESULTS: Almost half of the patients sensitized to epoxy resin were additionally sensitized to reactive diluents or hardeners. Among the reactive diluents, 1,6-hexanediol diglycidyl ether was the most frequent allergen, followed by 1,4-butanediol diglycidyl ether, phenyl glycidyl ether, and p-tert-butylphenyl glycidyl ether. Among the hardeners, m-xylylene diamine (MXDA) and isophorone diamine (IPDA) were the most frequent allergens. According to the calculated exposure-related frequency of sensitization, MXDA seems to be a far more important sensitizer than IPDA. Up to 60% of the patients sensitized to hardeners and 15-20% of those sensitized to reactive diluents do not react to epoxy resin. CONCLUSIONS: In cases of suspected contact allergy to an ERS, a complete epoxy resin series must be patch tested from the start.

Epidemiological data on airborne contact dermatitis - results of the IVDK.

BACKGROUND: Airborne contact dermatitis (AirbCD) is not uncommon, according to a large number of published case reports and review articles. Epidemiological data on AirbCD based on larger clinical samples have not yet been published. OBJECTIVES: To investigate demographic characteristics and patch test reactivity in patients diagnosed with both occupational and non-occupational AirbCD. METHODS: A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 1994-2013, including 201 344 consecutively patch tested patients, was performed. RESULTS: One thousand two hundred and three patients (0.6%) were diagnosed with AirbCD, 421 (35.0%) of these with an occupational background. Occupational dermatitis and face involvement were more prevalent than in patients without AirbCD (n = 200 141). Sensitization to epoxy resin and sensitization to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) were significantly associated with AirbCD, and there was a trend for sensitization to Compositae mix and/or sesquiterpene lactone mix to be associated with AirbCD. Adhesives, plastics, construction materials, paints and varnishes in occupational cases, and plants in non-occupational cases, were the most commonly documented culprit product categories. CONCLUSIONS: AirbCD is more common in patients with occupational dermatitis than in patients with non-occupational dermatitis. In our clinical sample, components of epoxy resin systems, MCI/MI and Compositae allergens were the most important contact allergens associated with AirbCD. Patch testing with additional allergens is important.

DKG statement on the use of metal alloy discs for patch testing in suspected intolerance to metal implants.

Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, 'prophetic'/prophylactic patch testing should not be performed. Pre-implant patch testing should only be done to verify or exclude metal allergy in patients with a corresponding history. In case of implant-related complications - in particular following replacement arthroplasty - such as pain, effusion, skin lesions, reduced range of motion or implant loosening, orthopedic causes should be ruled out first. Workup of suspected metal implant allergy should then be done using the DKG standard series, which includes nickel, cobalt, and chromium preparations. Various studies assessing the usefulness of metal alloy discs for patch testing have shown this particular approach to be ineffective with respect to providing reliable information on metal allergy. Any positive reaction in such tests cannot be assigned to a specific metal contained within the alloy. Furthermore, there is a risk of broad and indiscriminate use of these readily available discs. Accordingly, given the lack of additional benefit compared to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs.

Occupational contact allergy in the building trade in Germany: influence of preventive measures and changing exposure.

PURPOSE: Since 1993, assiduous efforts have been made in Germany to lower the incidence of allergic cement dermatitis by reducing the content of hexavalent chromium (Cr VI). Usage of epoxy resin systems has considerably increased in the building trade in the same period. We analysed data of the Information Network of Departments of Dermatology (IVDK) to evaluate the influence of these changing occupational exposures on frequencies of sensitization. METHODS: IVDK data of 1,153 men working in the building trade (bricklayers, tile setters etc.) presenting with occupational skin disease in the years 1994-2008 were analysed, taking into consideration not only the year of patch testing, but also beginning and duration of work in the building trade. RESULTS: While contact sensitization to chromate decreased from 43.1 to 29.0%, sensitization to epoxy resin increased from 8.4 to 12.4%. Logistic regression analysis revealed that, compared to those who had already worked before 1994, patients having started to work in building trade after 1999 had a significantly decreased risk of chromate sensitization (odds ratio 0.42) and a significantly increased risk of sensitization to epoxy resin (odds ratio 2.79). Additionally, risk of thiuram sensitization increased with the duration of employment. CONCLUSION: Our data confirm that reducing Cr VI content of cement is useful in preventing allergic cement eczema, as previously found in Scandinavia. In contrast, the increasing prevalence of contact sensitization to epoxy resin components in the building trade is alarming. Preventive measures, which have already been implemented, have to be enforced.

Patch testing with benzoyl peroxide: reaction profile and interpretation of positive patch test reactions.

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.