More than just methylisothiazolinone: Retrospective analysis of patients with isothiazolinone allergy in North America, 2017-2020.

BACKGROUND: Isothiazolinones are a common cause of allergic contact dermatitis. OBJECTIVE: To examine the prevalence of positive patch test reactions to isothiazolinones from 2017-2020 and characterize isothiazolinone-allergic (Is+) patients compared with isothiazolinone nonallergic (Is-) patients. METHODS: Retrospective cross-sectional analysis of 9028 patients patch tested to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) 0.02% aqueous, MI 0.2% aqueous, benzisothiazolinone (BIT) 0.1% petrolatum, and/or octylisothiazolinone (OIT) 0.025% petrolatum. Prevalence, reaction strength, concurrent reactions, clinical relevance, and source of allergens were tabulated. RESULTS: In total, 21.9% (1976/9028) of patients had a positive reaction to 1 or more isothiazolinones. Positivity to MI was 14.4% (1296/9012), MCI/MI was 10.0% (903/9017), BIT was 8.6% (777/9018), and OIT was 05% (49/9028). Compared with Is-, Is+ patients were more likely to have occupational skin disease (16.5% vs 10.3%, P <.001), primary hand dermatitis (30.2% vs 19.7%, P <.001), and be >40 years (73.1% vs 61.9%, P <.001). Positive patch test reactions to >1 isothiazolinone occurred in 44.1% (871/1976) of Is+ patients. Testing solely to MCI/MI would miss 47.3% (611/1292) of MI and 60.1% (466/776) of BIT allergic reactions. LIMITATIONS: Retrospective cross-sectional study design and lack of follow-up data. CONCLUSION: Sensitization to isothiazolinones is high and concurrent sensitization to multiple isothiazolinone allergens is common.

Professional Cleaners' and Healthcare Workers' Ability to Recognize Hand Eczema.

Timely intervention reduces the risk of a poor prognosis in hand eczema, making early recognition of symptoms important in high-risk professions. However, limited data exist regarding the ability of cleaners and healthcare workers to recognize hand eczema. The aim of this study was to examine cleaners' and healthcare workers' ability to recognize hand eczema in clinical photographs and to assess the severity of the disease. Cleaners and healthcare workers completed a questionnaire consisting of 16 questions and participated in a structured interview referring to a validated photographic severity guide for chronic hand eczema, which comprised clinical photographs of hand eczema at varying levels of severity. Eighty cleaners and 201 healthcare workers (total N = 281) participated in the study. The rates of correctly identified hand eczema in clinical photographs (cleaners/ healthcare workers) were: 41.2%/57.7% (mild hand eczema), 81.2%/92.0% (moderate hand eczema), 85.0%/94.5% (severe hand eczema) and 82.5%/97.0% (very severe hand eczema). The proficiency of healthcare workers in recognizing hand eczema was significantly higher than that of cleaners. The results indicate that a large proportion of cleaners and healthcare workers fail to recognize mild hand eczema in clinical photographs. Healthcare workers had higher success rates in recognizing hand eczema in all severity categories. Symptom underestimation may lead to under-reporting of the true prevalence of hand eczema, with consequent loss of opportunities for prevention.

Quality of patch testing patient's own material in patients with suspected occupational skin diseases throughout Germany: Interim results of the German Social Accident Insurance (DGUV) research project FB 317b.

BACKGROUND: Due to limited availability of commercial test preparations, patch testing patient's own material (POM) is of great importance to diagnose occupational allergic contact dermatitis. OBJECTIVES: To assess the quality of performance and documentation of patch testing with POM in patients with suspected occupational skin diseases (OSD) in Germany. METHODS: Retrospective-prospective analysis of protocols of patch tests with POM was conducted between 2013 and 2021 in patients with suspected OSD and submitted to statutory accident insurance institutions. Assessments were done by predefined criteria. RESULTS: Three thousand and four patch tests with POM from 460 patients were included. A full description of the POM was provided in 73.3% of all tests. The test concentration, test vehicle and pH value were documented in 74.3%, 70.5% and 42.2% of tests, for which the respective parameters were considered relevant. One hundred and sixty-one positive reactions to POM were documented. In 72%, sufficient patch testing with commercial test substances was conducted to investigate the positive reaction. In 30.4%, consecutive patch testing of all ingredients of the POM was done. CONCLUSIONS: The results not only show considerable shortcomings mainly in documentation but also to some extent performance of patch tests with POM in patients with suspected OSD in Germany.

Assessing the efficacy of a German-inspired intervention on occupational contact dermatitis in Denmark: A randomised controlled trial with 3-month follow-up.

BACKGROUND: Occupational contact dermatitis (OCD) is a prevalent, often chronic disease that poses a risk for job loss and decreased quality of life. In Germany, a multi-step prevention programme emphasising early detection and highly specialised multidisciplinary treatment has been implemented with great success. OBJECTIVES: To examine the effectiveness of a Danish-adapted version of the German prevention effort on OCD severity, quality of life and occupational consequences at 3-month follow-up. METHODS: Randomised, controlled trial. Participants were recruited after the first referral from General Practitioner to Dermatologist with suspected OCD. The intervention group (IG) received a Danish-adapted, multidisciplinary intervention, while the control group (CG) navigated the Danish healthcare system without interference from the study. OCD severity, occupational consequences and quality of life were assessed at 3-month follow-up using self-reported questionnaires. RESULTS: A statistically significant decrease in the severity of eczema was found at 3-month follow-up in the IG compared to the CG. The IG were statistically significantly more likely to have seen a dermatologist at 3-month follow-up. Higher treatment level in the IG was indicated by the results but was not statistically significant. No significant difference was found in quality of life or occupational consequences. CONCLUSIONS: These initial findings suggest that early and specialised treatment of OCD improves OCD prognosis.

Severely compromised supply of patch test allergens in Europe hampers adequate diagnosis of occupational and non-occupational contact allergy. A European Society of Contact Dermatitis (ESCD), European Academy of Allergy and Clinical Immunology (EAACI), European Academy of Dermatology and Venereology (EADV) task forces 'Contact Dermatitis' and 'Occupational Skin Disease' position paper.

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.

Nine years of patch testing with isocyanates in a clinic of occupational dermatology.

BACKGROUND: Isocyanates are used as starting materials of polyurethane (PU) products. They are relatively important occupational skin sensitizers. OBJECTIVES: To analyse results of a large isocyanate patch test series of 19 isocyanate test substances and 4,4'-diaminodiphenylmethane (MDA), a marker of 4,4'-diphenylmethane diisocyanate (MDI) hypersensitivity. METHODS: Test files were screened for positive reactions in the isocyanate series. Patients with positive reactions were analysed for occupation, exposure and diagnosis. RESULTS: In 2010-2019, 53 patients had positive reactions in the series (16% of 338 patients tested). MDA, the well-established screening substance for MDI allergy, was positive in 30 patients, an in-house monomeric MDI test substance in 23 patients and 3 different polymeric MDI test substances in 19-21 patients. We diagnosed 16 cases of occupational allergic contact dermatitis (OACD) from MDI including 3 pipe reliners. Hexamethylene-1,6-diisocyanate (HDI) oligomers in paint hardeners caused 5 cases of OACD, more cases than 2,4-toluene diisocyanate (TDI; n = 3) and isophorone diisocyanate (IPDI; n = 1) put together. CONCLUSIONS: In contrast to previous studies, polymeric MDI test substances were not superior to a monomeric MDI. Pipe reliners may get sensitised not only by epoxy products and acrylates but also by MDI in hardeners of PU pipe coatings. HDI oligomers were the second most important causes of OACD after MDI.

Frequency and clinical relevance of contact allergy in dental patients.

BACKGROUND: While many studies have reported on occupational allergic contact dermatitis amongst dental personnel, studies on the relevance of patch testing in dental patients are scarce. OBJECTIVES: To determine the frequency and clinical relevance of contact allergy in patients with intra- and perioral complaints. METHODS: A total of 360 patients with intra- and perioral complaints suspected of having a contact allergy were patch-tested with the dental allergen series, European Baseline Series, and extended Amsterdam Baseline Series at Amsterdam University Medical Centers between January 2015 and November 2021. RESULTS: A total of 285 patients (79.2%) had a positive patch test reaction for either one (18.6%) or multiple allergens (60.6%). Sodium tetrachloropalladate was the most sensitising allergen with 98 patients (27.2%) testing positive, followed by nickel sulphate (23.3%), methylisothiazolinone (15.6%), and fragrance mix I (14.2%). Clinical relevance was found in 68 of 208 patients (32.7%), with patients having one (15.4%) or multiple (17.3%) patch test reactions clinically relevant to their (peri)oral complaints. CONCLUSIONS: Clinically relevant patch test reactions were frequently seen in dental patients. Although this study provides us with a better understanding on the frequency and clinical relevance of contact allergy in dental patients, further studies are needed to confirm our results.

Results of patch testing 2-hydroxyethyl methacrylate (HEMA) in the European baseline series: A 4-year retrospective study.

BACKGROUND: 2-Hydroxyethyl methacrylate (HEMA) was added to the European baseline series (EBS) in 2019. Few recent data are available on the frequency and relevance of positive reactions to this hapten. OBJECTIVES: To investigate the frequency and relevance of positive patch tests to HEMA in the EBS in a university hospital in Amsterdam, The Netherlands. PATIENTS AND METHODS: Retrospective study in patients with positive patch tests to HEMA investigated between June 2019 and August 2023. RESULTS: Of 2927 consecutive patients, 88 (79 women and 9 men; 3.0%) had a positive reaction to HEMA. The prevalence in women was 3.9%, in men 1.0%. Forty-three (49%) reactions were judged to be of current clinical relevance and 21 (24%) of past relevance. In this group of 64 patients with relevant reactions, 18 (28%) had occupational contact with (meth)acrylate-containing products, of who 11 (61%) were nail stylists. In 46 patients with non-occupational allergic contact dermatitis, 31 (67%) had allergic reactions to nail cosmetics. Glues and glue-containing products accounted for 22% of the materials causing allergic contact dermatitis and dental products for 8%. CONCLUSIONS: Allergic reactions to HEMA are very frequent in women investigated in Amsterdam. Nearly two thirds of cases were caused by nail cosmetics.

Impact of atopic dermatitis on occupational contact dermatitis among young people: A retrospective cohort study.

BACKGROUND: Occupational contact dermatitis (OCD) is a common occupational disease. Atopic dermatitis (AD) is a known risk factor for OCD. OBJECTIVES: To determine the prevalence of previously diagnosed AD among young workers with recognized OCD and assess its impact on OCD prognosis. METHODS: A retrospective cohort study. A questionnaire was sent to 6251 workers with recognized OCD who were under 35 years at notification (response rate: 47%). Of the respondents, 2392 answered a question about previous doctor-diagnosed AD and were included in the study. Eczema severity, occupational consequences and quality of life were examined using statistical analyses comparing workers with and without previously diagnosed AD. RESULTS: The prevalence of previously diagnosed AD was 41.8% (95% CI: 39.8-43.8). Women had a higher AD prevalence, and workers with AD reported OCD at a younger age. Workers with AD reported more frequent and severe eczema symptoms and had a higher risk of OCD negatively affecting job and occupation choices. Health-related quality of life was more adversely affected in workers with AD. CONCLUSIONS: AD significantly impacts severity and has long-term consequences for young people with OCD. Targeted prevention strategies need to be developed.

The correlation between self-reported hand eczema and clinically based diagnosis in professional cleaners.

BACKGROUND: Most studies investigating the prevalence of hand eczema (HE) in professional cleaners use self-reported questionnaire-based data. However, no validation studies of self-reporting of HE among professional cleaners have previously been conducted. OBJECTIVES: To investigate (1) the point prevalence of self-reported HE, (2) the point prevalence of HE estimated by physical examination of the hands and (3) the sensitivity and specificity of self-reporting of HE compared with the diagnosis based on physical examination among professional cleaners. METHODS: Professional cleaners at three different hospitals in Region Zealand were invited to fill out a questionnaire. The point prevalence of self-reported HE was estimated based on questions from the Nordic Occupational Skin Questionnaire. After completing the questionnaire, each cleaner underwent a physical examination of the hands by a dermatologist on the same day. RESULTS: In total, 234 cleaners were invited to participate in the study, and 224 (response rate = 96.0%) agreed to take part. Based on the self-reported questionnaires, 5.3% (n = 12) of the cleaners had current HE. Based on an examination by a physician, 19.2% (n = 43) of the cleaners had current HE. The sensitivity of self-reported HE was found to be 28.0%, while the specificity was found to be 100.0%. The positive predictive value was found to be 100.0%, while the negative predictive value was 85.0%. CONCLUSION: The true point prevalence of HE among professional cleaners is underestimated when based on self-reporting.

2-Cyanoethyl dimethyldithiocarbamate, a new contact allergen found in accelerator-free nitrile gloves.

BACKGROUND: Allergic contact dermatitis (ACD) from rubber glove usage is usually caused by rubber additives such as the accelerators. However, in analyses of the suspected gloves, ordinary rubber allergens are not always found. Accelerator-free rubber gloves are available, but some patients with accelerator allergy do not tolerate them and might also be patch test positive to them. OBJECTIVES: To identify and chemically characterize a new allergen, 2-cyanoethyl dimethyldithiocarbamate (CEDMC), in rubber gloves. We describe two patient cases: patient 1 that led us to the identification of CEDMC and patient 2 with occupational ACD caused by CEDMC. METHODS: The patients were examined with patch testing including baseline and rubber series, and their own rubber gloves. High-performance liquid chromatography (HPLC) was used for chemical analysis of rubber gloves. The allergen was synthesized and identified by nuclear magnetic resonance, mass spectrometry and infrared spectrometry, and tested on patient 2. RESULTS: CEDMC was identified by HPLC in a nitrile glove associated with hand eczema in patient 1. Patient 2 whose nitrile gloves contained CEDMC was patch test positive to CEDMC. CONCLUSIONS: CEDMC is a new contact allergen in nitrile gloves and probably forms during vulcanization from residual monomer acrylonitrile and rubber additives.

Occupational exposure to epoxy components and risk of dermatitis: A registry-based follow-up study of the wind turbine industry.

BACKGROUND: Allergic contact allergy and dermatitis are frequently reported among epoxy-exposed workers. OBJECTIVES: To determine the risk of dermatitis associated with epoxy exposure. METHODS: We followed 825 epoxy-exposed and 1091 non-exposed blue-collar workers, and 493 white-collar workers of a Danish wind turbine blade factory during 2017-2022 with linked data from national health registers on diagnoses, patch testing, or fillings of prescriptions for topical corticosteroids. Incidence rate ratios of dermatitis or a first-time topical corticosteroid prescription were estimated with Poisson regression using non-exposed blue-collar workers as reference. We similarly estimated incidence rate ratios for the duration of epoxy exposure and current epoxy exposure. RESULTS: Epoxy-exposed blue-collar workers showed a dermatitis incidence rate of 2.1 per 100 000 person days, a two-fold increased risk of dermatitis and a 20% increased risk of filling a prescription for topical corticosteroids. Incidence rate ratios were higher during early exposure and declined with further exposure for both outcomes. White-collar workers had generally lower risks. CONCLUSION: We observed an increased risk of dermatitis following epoxy exposure confirming previous case reports and cross-sectional studies emphasizing the need for intensified focus on preventive efforts for this group of workers.

Contact sensitization and self-reported eczema in Swedish painters with occupational exposure to isothiazolinones.

BACKGROUND: Due to an increasing occupational usage of isothiazolinone (IT)-containing preservatives, and their potential to cause skin sensitization and allergic contact dermatitis, that is, chronic disease, there is a need for more knowledge on how highly exposed workers are affected. OBJECTIVES: The overall objective was to explore dermatological symptoms of potentially long-lasting or chronic character in Swedish painters. METHODS: Building painters from western and southern Sweden were initially invited to perform a questionnaire on occurrence of skin symptoms. Participants with affirmative responses, and the right inclusion criteria, were further invited to patch testing with four different ITs: benzisothiazolinone (BIT), methylisothiazolinone, methylchloroisothiazolinone and octylisothiazolinone. RESULTS: There was a tendency towards higher occurrence of positive patch test reactions among the painters compared with occupationally unexposed registry patients; however, not statistically significant differences. BIT was the substance most frequently causing positive test results in both groups. The occurrence of adult-onset eczema was higher in painters than in the control group of electricians, and just shy of statistical significance concerning any of several skin locations (face/legs/arms/hands). CONCLUSION: Building painters present with positive patch test reactions to common paint preservatives (ITs), and they report adult-onset eczema more often than do less occupationally exposed groups.

Epidemiological case-control study on contact sensitisation in female foot care specialists with occupational contact dermatitis: Patch test data of the Information Network of Departments of Dermatology (IVDK), 2008 to 2022.

BACKGROUND: Mainly women work as foot care specialists (FCS). They are at risk to develop occupational dermatitis (OD). OBJECTIVES: The objective of this study is to describe the contact sensitisation pattern of female FCS with OD. METHODS: In a retrospective study, patch test and clinical data collected by the Network of Departments of Dermatology (IVDK) from 2008 to 2022 were analysed. Data of 116 female FCS with OD were compared with data of 13 930 female patients with OD working in other professions and 78 612 female patients without OD. RESULTS: Hand dermatitis (93.1%) was significantly more common and face dermatitis (0.9%) significantly less common in female FCS with OD compared to other female patients with or without OD. Frequent suspected allergen sources were disinfectants, gloves, leave-on and nail cosmetics. Occlusion and wetness were important co-factors. The most common diagnoses were irritant contact dermatitis (26.7%) and allergic contact dermatitis (21.6%). No sensitisation to any of the baseline series allergens was significantly more frequent in female FCS with OD than in the two control groups. However, sensitisations to allergens which FCS are abundantly exposed to, including fragrances, preservatives, rubber ingredients and disinfectants, were most common. CONCLUSIONS: FCS should be aware of the OD risk and prevention should be promoted.

Managing Allergic Nickel Dermatitis in Occupational Settings: A Case Report.

Contact dermatitis is a common cutaneous inflammatory condition, triggered by exposure to irritant substances or allergens. Nickel is the most prevalent allergen, a metal widely used in accessories, furniture, office materials, food and in industry, with multiple exposure pathways, making it difficult to assess which exposure is causing allergic dermatitis. Here, we report a case of an administrative worker with chronic hand eczema, limited to the radial metacarpophalangeal region of the left hand, caused by occupational exposure to nickel, confirmed by nickel deposition test on the hand and a positive test with a metallic stapler used at her workplace.

Occupational Hand Dermatitis.

PURPOSE OF REVIEW: Occupational hand dermatitis is a common work-related disorder of the skin. Prevention and management of this disease is critical to improving workers' quality of life and for occupation-specific retention. RECENT FINDINGS: This is a critical review of the current literature on occupational hand dermatitis. Occupational dermatitis continues to have a high prevalence among workers although the overall incidence may be slowly decreasing. Irritant contact dermatitis due to wet work exposure is the most common cause of occupational hand dermatitis. Healthcare workers, hairdressers, and metal workers are at particularly high risk for this disease. While some prevention programs have been ineffective in mitigating occupational hand dermatitis, other more resource-intensive initiatives may have benefit. Continued research is needed on ways to manage wet work exposures and on scalable, effective prevention programs for occupational hand dermatitis. The spectrum of culprit contact allergens continues to evolve, and vigilance for potential occupation-specific allergens remains important.

Diagnostics and Prevention of Occupational Allergy in Hairdressers.

PURPOSE OF REVIEW: This study aims to provide an overview on current knowledge on occupational allergic diseases in hairdressers and up-to-date perspectives of prevention. RECENT FINDINGS: Hand eczema (dermatitis) is common in hairdressers, often caused by contact allergy to one or multiple small molecules (haptens) used, e.g., for dyeing, bleaching, and waving/relaxing or by ancillary substances such as preservatives. Hairdressers, compared to other patch-tested patients, have an up to fivefold increased risk to be found sensitized, e.g., against p-phenylenediamine, ammonium persulfate, and glyceryl thioglycolate. Some of these small molecules may induce respiratory sensitization causing allergic rhinitis and/or asthma, notably persulfate salts. Occupational hazards in hairdressing are well described. This knowledge needs to be put into use for risk reduction, mainly by substitution of allergenic ingredients by less allergenic ones, education, and use of ventilation and suitable single-use gloves.

Increased Rates of Gold and Acrylate Allergy in Individuals with Fibromyalgia Tested with an Extended Dental Patch Test Series.

Fibromyalgia is a common chronic pain condition. Rates of contact allergy in individuals with fibromyalgia have not been widely studied. Systemic contact allergy can present with muscle and joint pain and general malaise. The aim of this study is to investigate contact allergy rates in individuals with fibromyalgia to the sensitizers in an extended dental series and compare with control groups. Contact allergy to gold was significantly more common in the fibromyalgia group than the dermatitis control group. When corrected for patch test system, contact allergy to gold was significantly more common in the fibromyalgia group than the dental control group. Contact allergy to hydroxyethyl methacrylate and grouped acrylates and methacrylates was significantly more common in the fibromyalgia group than the dental control group. In conclusion, individuals with fibromyalgia may have a propensity to sensitization to gold, either via an increased exposure or an alteration in the oral environment. Gold is also implicated in systemic contact dermatitis and may be a factor in elicitation of symptoms in individuals with fibromyalgia. Acrylate allergy is also common in the fibromyalgia population and may be a consequence of occupational exposure or dental treatment.

Nickel release from hairdressing tools in the United States.

BACKGROUND: Hairdressers have a high prevalence of contact dermatitis, especially to nickel. The presence of nickel in hairdressing tools has been evaluated in the European Union, where the government limits nickel release levels from objects. OBJECTIVES: The aim of this study is to qualitatively investigate nickel release in hairdresser tools in both rural and urban United States, a country without nickel release legislation. METHODS: Hairdressers and individuals with hairdressing tools were invited to participate. Metallic parts of each tool were tested with dimethylglyoxime (DMG), which detects nickel release. Data on tool cost were recorded. RESULTS: A total of 89 tools from 9 salons and 2 over-the-counter sets were tested. Twenty-four (27%) tested positive: trimmers (100%), curling irons (100%), clippers (50%), hair clips (36%), texturizing shears (26%), and trimming shears (4%). Nickel was detected in both salon and over-the-counter tools, and rural and urban salons. Nickel-releasing tools were cheaper than DMG-negative tools of the same type. CONCLUSIONS: Our findings help explain the high prevalence of contact dermatitis among hairdressers, alert clinicians to consider occult occupational nickel when assessing patients with allergic contact dermatitis, reinforces the importance of using barrier protection including gloves when handling hairdressing tools including at home, and augments impetus for more legislation regulating common allergens.

Epoxy allergy, investigation of a modern industry.

BACKGROUND: Five workers from an industry manufacturing various articles from carbon fibre reinforced epoxy plastics were referred to our department because of suspected occupational allergic contact dermatitis (OACD). When patch tested, four of them had positive reactions to components of epoxy resin systems (ERSs) that could explain their current skin problems. All of them had been working at the same workstation at a specially designed pressing machine, with operations including manually mixing epoxy resin with hardener. Multiple cases of OACD in the plant prompted an investigation including all workers with possible risk exposures at the plant. OBJECTIVES: To investigate the prevalence of occupational dermatoses and contact allergies among the workers at the plant. MATERIALS AND METHODS: Totally 25 workers underwent investigation that included a brief consultation with a standardized anamnesis and clinical examination followed by patch testing. RESULTS: ERSs-related reactions were found in 7 of the 25 investigated workers. None of the seven had a history of previous exposure to ERSs and they are regarded as sensitized through work. CONCLUSIONS: Twenty-eight percent of investigated workers showed reactions to ERSs. Of these the majority would have been missed if supplementary testing would not have been added to testing with the Swedish base line series.