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.

[Is occupational allergic contact dermatitis within the armed forces an unrecognized problem?] / Kontaktallergiskt eksem ­ vanlig arbetsskada i försvaret?

In the armed forces, marching still remains a major component in the training of the young recruits. In the following we describe a young recruit who, following instructions, prophylactically used adhesives to prevent chafing. The recruit developed an allergic contact dermatitis with generalized spreading. The adhesive products recommended are sold on a global market and are extensively used.  Allergic contact dermatitis from these products have so far only been reported from Sweden. Unfortunately, even though the first cases were reported some years ago, new cases are still diagnosed. When medical devices are recommended to be used on the skin for a prolonged time and under extreme conditions, sensitization and a subsequent allergic contact dermatitis must be considered.

Preservative contact allergy in occupational dermatitis: a machine learning analysis.

Occupational dermatoses impose a significant socioeconomic burden. Allergic contact dermatitis related to occupation is prevalent among healthcare workers, cleaning service personnel, individuals in the beauty industry and industrial workers. Among risk factors, the exposure to preservatives is frequent, since they are extensively added in products for occupational use. The goal of this study is to investigate the contact allergy patterns in order to understand the linkage among hypersensitivity to preservatives, occupational profiles, patients' clinical and demographic characteristics. Patch test results were collected from monosensitized patients to Formaldehyde 2%, KATHON 0.02%, thimerosal 0.1%, and MDBGN 0.5%; information was also collected for an extended MOAHLFA (Male-Occupational-Atopic-Hand-Leg-Face-Age) index. To assess the relationship between allergen group and occupational-related ACD, the chi-square test for independence was utilized. To uncover underlying relationships in the data, multiple correspondence analysis (MCA) and categorical principal components analysis (CATPCA), which are machine learning approaches, were applied. Significant relationships were found between allergen group and: occupation class, atopy, hand, leg, facial, trunk, neck, head dermatitis, clinical characteristics, ICDRG 48 h and ICDRG 72 h clinical evaluation. MCA and CATPCA findings revealed a link among allergen group, occupation class, patients' demographic and clinical characteristics, the MOAHLFA index, and the ICDRG scores. Significant relationships were identified between the allergen group and various manifestations of dermatitis. The utilization of machine learning techniques facilitated the discernment of meaningful patterns in the data.

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.

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.

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.

The prevalence of hand dermatitis among intensive care unit nurses.

BACKGROUND: Healthcare workers are at high risk of developing occupational hand dermatitis (HD) due to their frequent exposure to wet-work and use of gloves. Complaints of HD may interfere with work and cause loss of work productivity, or sick leave, and may have impact on job pleasure and performing daily activities. The prevalence of HD among intensive care unit (ICU) nurses is unknown. OBJECTIVES: To investigate the point prevalence and the 1-year prevalence of HD among ICU nurses, and to determine the impact of HD on work and daily activities. METHOD: A questionnaire-based cross-sectional study was performed among ICU nurses. Participants were recruited in the Amsterdam University Medical Centre. A symptom-based questionnaire was used to determine HD and atopic predisposition, and an additional questionnaire was used concerning the influence of HD. ICU nurses with an atopic predisposition or symptoms suiting HD were invited for the hand dermatitis consultation hour (HDCH). Data were analysed with logistic regression. RESULTS: A total of 184 ICU nurses were included. The point prevalence of HD was 9.8% (95% CI: 5.9-15.0) and the 1-year prevalence was 26.6% (95% CI: 20.4-33.6). Sick leave was reported by 0.5%. HD seemed to have more impact on job pleasure than on work productivity. CONCLUSION: The high prevalence rate of HD resulting from our study highlights the need for the prevention of occupational HD among healthcare 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.

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.

Associations between tobacco smoking status and patch test results-A cross-sectional pilot study from the Information Network of Departments of Dermatology (IVDK).

BACKGROUND: Earlier studies suggested a potential association between tobacco smoking and nickel sensitization, but little is known about other contact allergens. OBJECTIVES: To investigate the association of smoking status and contact sensitizations as well as subtypes of dermatitis, and to analyse the sensitization profiles of tobacco smokers. PATIENTS AND METHODS: Within the Information Network of Departments of Dermatology (IVDK), we performed a cross-sectional multicentre pilot study comprising 1091 patch-tested patients from 9 departments, comparing 541 patients with a history of cigarette smoking (281 current and 260 former smokers) with 550 never-smokers. RESULTS: We could not confirm the previously reported association between nickel sensitization and tobacco smoking. Moreover, sensitizations to other allergens, including colophony, fragrance mix I, Myroxylon pereirae and formaldehyde, were not increased in cigarette smokers compared with never smokers. Hand dermatitis (50.6% vs. 33.6%) and occupational cause (36.2% vs. 22.5%) were significantly more frequent among cigarette smokers compared with never-smokers as shown by non-overlapping 95% confidence intervals. CONCLUSIONS: Although our study does not allow a firm conclusion on whether smoking status contributes to certain contact sensitizations, it confirms an association of smoking with hand dermatitis and occupational cause.

Methylisothiazolinone sensitisation in New Zealand is decreasing.

BACKGROUND/OBJECTIVES: In the last 10 years methylisothiazolinone (MI) emerged as a global cause of preservative-related ACD. New Zealand has liberal regulations for the MI concentration limit in cosmetic products compared to Europe and Australia. The aim of this study was to evaluate the prevalence of MI sensitisation in New Zealand, explore sources of MI exposure and make recommendations on New Zealand regulations for MI use. METHODS: This retrospective study included data from patients who underwent patch testing with MI from 2008 to 2021 in a tertiary hospital dermatology clinic and a private dermatology clinic in Auckland, New Zealand. Patient baseline characteristics were recorded along with results of patch testing. Sources of MI exposure were identified from medical records. RESULTS: Over the study period, 1049 patch tests were performed in 1044 patients. MI was only tested as a stand-alone allergen from 2015; positive reactions to MI increased from 5.3% in 2015 to a peak of 11.9% in 2017 and then decreased to 6.4% in 2021. The most common source of MI exposure was shampoo or conditioner (27.7% of all relevant reactions) followed by occupational exposures to paints, biocides or glue (19.1%). CONCLUSION: Both sensitisation and ACD to MI appear to be decreasing, likely secondary to changes in product compounding due to stricter concentration limits internationally. We recommend New Zealand adopt lower MI concentration limits for cosmetics to match the limits of Australia and Europe.

How Allergists Can Perform an Occupational History in Every Patient.

The occupational history is often neglected in the routine evaluation of new patients with asthma, chronic rhinitis, or dermatologic complaints. Such omissions are inadvertent because work-related conditions are often not prioritized. There also may be lack of awareness of the scope of respiratory or cutaneous allergens capable of inducing occupational asthma (OA) or work-related contact dermatitis. Evidence exists suggesting that the occupational history is often neglected among primary care physicians and specialists. Failure to diagnose OA in a timely fashion by identifying occupational sources of exposure, for example, may result in unnecessary morbidity in workers whose exposure is not modified. In this commentary, we propose a brief intake survey to be administered to all patients coming to an allergy practice to quickly screen for possible work-related respiratory symptoms and another for occupational dermatitis. This would require minimal physician time and could be self-administered at the initial encounter and incorporated into the medical record. A positive response to either survey should trigger a more detailed evaluation by the allergy specialist. More detailed approaches for stepwise clinical evaluation of the worker suspected of OA and contact dermatitis are discussed.

Artificial nail modelling systems in healthcare workers: An emerging risk of contact sensitization to a well-known occupational allergen in an alternative way.

BACKGROUND: Artificial nail modelling systems (ANMS) pose a significant risk for nail stylists and their clients regarding acrylate sensitization, which might jeopardize the use of acrylate-containing medical devices. OBJECTIVES: To evaluate the frequency of artificial nail practices among female healthcare workers (HCWs) compared with controls and assess ANMS-related side effects. METHODS: In this comparative, cross-sectional, single-centre study, a face-to-face interview with 200 female HCWs and 200 age-matched female dermatology patients (controls) was conducted regarding the use of ANMS between March and November 2023. RESULTS: Among 400 participants (median age: 25), 85 (21.3%) have applied ANMS at least once. The prevalence of ANMS application was significantly higher in HCWs (n = 54/200, 27%) compared with controls (n = 31/200, 15.5%) (p < 0.05). Long-lasting nail polish was the most commonly preferred technique (n = 82/85, 96.5%). ANMS were mainly performed in nail studios by nail stylists (n = 79/85, 92.9%), while three participants were using home kits. Nail brittleness was the most frequently reported side effect (n = 19/85, 22.4%). No case of allergic contact dermatitis (ACD) was detected. CONCLUSIONS: The popularity of ANMS among young female HCWs is growing. This striking trend might further put these individuals not only at risk of medical device-related adverse events but also occupational ACD.

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.