Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis.

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis.

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.

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.

Prevalence and incidence of hand eczema in healthcare workers: A systematic review and meta-analysis.

Healthcare workers (HCWs) are considered a high-risk group for developing hand eczema (HE), mainly owing to wet work and contact with allergens at work. To meta-analyse the prevalence and incidence of HE in HCWs, as well as mapping the prevalence of atopic dermatitis (AD) and HE severity in HCWs. A systematic review and meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines. Published literature from 2000 to 2022 was eligible based on predefined inclusion and exclusion criteria. A total of 18 studies were included. Pooled life-time, 1-year and point prevalence of self-reported HE in HCWs was 33.4% (95% confidence interval [CI]: 28.3-38.6), 27.4% (95% CI: 19.3-36.5) and 13.5% (95% CI: 9.3-18.4), respectively. AD prevalence was 15.4% (95% CI: 11.3-19.9). Overall, the majority of HCWs reported mild HE. One included study assessed HE incidence reporting 34 cases/1000 person years. Most studies scored low-moderate using the New Ottawa Scale and the pooled point prevalence data showed broad CIs. In conclusion, the high prevalence of HE in HCWs underlines the increased risk and need for preventive measures for this professional group. There is, however, a need of further standardized high-quality studies.

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.

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.

Bleaching powders, bleaching creams and other hair lightening preparations as sources for (airborne) allergic contact dermatitis and other health effects in hairdressers: Results of an empirical study.

BACKGROUND: Various products are available for lightening hair. There are no data on which applications are actually used in hairdressing, impeding proper estimation of actual exposure and necessary preventive measures. OBJECTIVES: To assess information about availability, usage and formulation of lightening preparations in the German hairdressing trade. METHODS: A market survey was conducted and hairdressers were surveyed by online questionnaires. RESULTS: Of 783 hairdressers clicking the link, 565 hairdressers (91.2% female, mean age of 40.2 ± 11.7 years) from all German states responded (response rate: 72.2%). The questionnaire survey has shown that available hair-lightening preparations in the German hairdressing trade are (multiple selection possible): dust-free (88.5%) and non-dust-free bleaching powders (22.1%), bleaching creams (41.9%), high-lifting hair colour creams (88.8%) and normal hair colour creams (58.4%). Five hundred eighteen (91.7%) hairdressers favour lightening hair with powder. The market survey revealed that bleaching powders and creams contain potassium persulfate, ammonium persulfate and sodium persulfate or combinations of these persulfate salts. CONCLUSIONS: Hairdressers are exposed to various hair-lightening applications containing different chemicals. Preventive measures need to address adverse skin and respiratory effects. Implementation of targeted health education already in early career stages (i.e., apprenticeship) seems advisable and can be maintained by refresher trainings.

Effects of impermeable and semipermeable glove materials on resolution of inflammation and epidermal barrier impairment after experimental skin irritation.

BACKGROUND: Semipermeable membranes might be suitable for glove liners or comfort gloves in individuals with irritant contact dermatitis (ICD). OBJECTIVES: To evaluate the effects of different glove materials on inflammation and epidermal barrier impairment after experimental skin irritation. METHODS: Nine test areas on the volar forearms of 24 healthy volunteers were irritated with sodium lauryl sulfate (1%) and afterward covered for 6 days (6 or 8 h/day) with semipermeable Sympatex (SYM), vinyl (OCC), combinations of vinyl with Sympatex (SYM/OCC) or cotton (COT/OCC), or left uncovered (CON). Up to day 10, measurements of transepidermal water loss (TEWL), erythema (a*), skin humidity (SH) and visual scoring (VS) were applied. RESULTS: No significant differences in skin parameters were found between COT/OCC and SYM/OCC as well as between each of the combinations and CON. SYM, COT/OCC and SYM/OCC led to better results for most skin parameters than OCC alone. CONCLUSIONS: Occlusive material has a negative impact on skin barrier recovery and inflammation after skin irritation whereas SYM is not inferior to uncovered areas indicating good tolerability. Altogether, the data suggest that SYM is a useful alternative to COT as material for glove liners and comfort gloves in ICD patients.

Systematic review on skin adverse effects of important hazardous hair cosmetic ingredients with a focus on hairdressers.

BACKGROUND: The burden of occupational hand eczema in hairdressers is high, and (partly strong) allergens abound in the hair cosmetic products they use. OBJECTIVES: To systematically review published evidence concerning contact allergy to an indicative list of active ingredients of hair cosmetics, namely, p-phenylenediamine (PPD), toluene-2,5-diamine (PTD), persulfates, mostly ammonium persulfate (APS), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG), concerning the prevalence of sensitization, particularly in terms of a comparison (relative risk; RR) between hairdressers and non-hairdressers. METHODS: Following a PROSPERO-registered and published protocol, eligible literature published from 2000 to February 2021 was identified, yielding 322 publications, and extracted in standardized publication record forms, also considering risk of bias. RESULTS: Based on 141 publications, the contact allergy prevalence to PPD was 4.3% (95% CI: 3.8-4.9%) in consecutively patch tested patients. Other ingredients were mostly tested in an aimed fashion, yielding variable, and partly high contact allergy prevalences. Where possible, the RR was calculated, yielding an average increased sensitization risk in hairdressers of between 5.4 (PPD) and 3.4 (ATG). Additional evidence related to immediate-type hypersensitivity, experimental results, exposures, and information from case reports was qualitatively synthesized. CONCLUSIONS: An excess risk of contact allergy is clearly evident from the pooled published evidence from the last 20 years. This should prompt an improvement in working conditions and product safety.

Respiratory toxicity of persulphate salts and their adverse effects on airways in hairdressers: a systematic review.

OBJECTIVE: To review the literature on respiratory effects of persulfate salts (PS) or hair bleaches in hairdressers and animal models exploring mechanisms behind PS-induced asthma. METHODS: A systematic review according to the PRISMA guidelines was performed. Studies published from 2000 to July 2021 that fulfilled predefined eligibility criteria were retrieved. Data were not quantitatively synthesized due to the heterogeneity of study designs, outcomes and methods. RESULTS: Forty-two articles were included. PS are indicated as the main cause of occupational rhinitis and asthma in hairdressers, and one of the leading causes of occupational asthma in some European countries. Bleaching products are indicated as the most important factor for development of respiratory symptoms, lung function decline, and leaving the hairdressing profession. Risk estimates from a good quality prospective study showed up to 3.9 times higher risk for wheezing and breathlessness in hairdressers aged ≥ 40 years than in matched controls, and 20 times higher risk in hairdressers to develop respiratory symptoms from exposure to bleaching powder than controls. Pathophysiological mechanisms of the respiratory response to PS are not yet fully elucidated, but may include non-specific and specific immune responses. CONCLUSIONS: Hairdressing is associated with a wide spectrum of respiratory adverse effects, of which bleaching products were indicated as the most hazardous. Preventive measures for reducing inhalatory exposure to PS in hair salons should be re-evaluated, including adopting occupational exposure limits at EU level, and encouraging use of safer bleach formulations. PROSPERO REGISTRATION NUMBER: CRD42021238118.

Nickel and cobalt release from beauty tools: A field study in the German cosmetics trade.

BACKGROUND: Relevant nickel and cobalt release from hairdressing tools has recently been evidenced. Comparable data are not available for tools used in beauty salons. OBJECTIVES: Screening of beauty tools for nickel and cobalt release. METHODS/MATERIALS: Three hundred eight beauty tools were tested in seven beauty salons located in two North-German states. A nickel spot test and a cobalt spot test were used to test the tools for nickel release and cobalt release, respectively. RESULTS: One hundred forty-three of 308 beauty tools overall (46.4%; 95% confidence interval [CI]: 40.8%-52.2%) released nickel and 18 of 308 beauty tools overall (5.8%; 95%CI: 3.5%-9.1%) released cobalt. Nickel release was found in 22 of 99 metal tools (22.2%; 95%CI: 14.5%-31.7%) and 121 of 209 tools with metallic parts (57.9%; 95%CI: 50.9%-64.7%); cobalt release was detected in 3 of 99 metal tools (3.0%; 95%CI: 0.63%-8.6%) and 15 of 209 tools with metallic parts (7.2%; 95%CI: 4.1%-11.6%). CONCLUSIONS: Nickel and cobalt are emitted at allergologically relevant levels by a wide range of beauty tools (i.e., metal tools and tools with metallic parts) utilized in the German cosmetics trade. Beauty tools should thus be considered occupational sources of nickel and cobalt exposure.

Occupational contact dermatitis among young people in Denmark - A survey of causes and long-term consequences.

BACKGROUND: Studies on the causes and consequences of occupational contact dermatitis (OCD) among young workers are non-existent. OBJECTIVES: Determine causes and consequences of OCD among workers younger than 35 years of age. METHODS: A questionnaire was sent to 6251 workers younger than 35 years at notification with recognized OCD (response rate 47%). RESULTS: The most prevalent occupations were health care workers, kitchen workers, nursery teachers, and hairdressers and beauticians. Seventy-six percent still had eczema, and 77% of these had eczema half to all the time over the last 3 months, with 61% evaluating their eczema as moderate to very severe. Fifty-three percent had changed their occupation since notification, and 42.5% had lost their job because of OCD. Allergic OCD increased the odds ratio (OR) for facial or foot eczema, job loss, change in work tasks, difficulties finding work, decrease in income, and sick leave. Age at notification of 25 years of age or younger increased the risk of job loss and feeling restricted in choice of job. Workers in the food industry had a higher OR for job loss, whereas hairdressers and beauticians had a higher risk of job loss and a decrease in income. CONCLUSIONS: The severe, long-term consequences of OCD notification signify the need for further preventive strategies among young workers.

European patch test results with audit allergens as candidates for inclusion in the European Baseline Series, 2019/20: Joint results of the ESSCAA and the EBSB working groups of the ESCD, and the GEIDACC.

BACKGROUND: In 2019, a number of allergens (haptens), henceforth, "the audit allergens," were considered as potential additions to the European Baseline Series (EBS), namely, sodium metabisulfite, 2-bromo-2-nitropropane-1,3-diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5% or 5% pet), linalool hydroperoxides (lin-OOH), limonene hydroperoxides (lim-OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, and lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments as well. OBJECTIVES: To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe. METHODS: Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the European Surveillance System on Contact Allergies testing these, as well as further collaborators from the EBS working group of the European Society of Contact Dermatitis (ESCD), and the Spanish Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. As patch test outcome, reactions between day (D) 3 and D5 were considered. RESULTS: Altogether n = 12 403 patients were tested with any of the audit allergen. Positive reactions were most common to lin-OOH 1% pet. (8.74% [95%CI: 8.14-9.37%]), followed by lin-OOH 0.5% pet., and lim-OOH 0.3% pet (5.41% [95% CI: 4.95-5.89%]). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72% (95% CI: 4.2-5.28%), followed by sodium metabisulfite 1% pet. (3.75% [95%CI: 3.32-4.23%]) and Compositae mix 5% pet. (2.31% [95% CI: 1.84-2.87%]). For some allergens, clinical relevance was frequently difficult to ascertain. CONCLUSIONS: Despite many positive patch test reactions, it remains controversial whether lin- and lim-OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion and ultimately decision on their implementation into routine testing among the ESCD members.

Prevalence and incidence of hand eczema in hairdressers-A systematic review and meta-analysis of the published literature from 2000-2021.

BACKGROUND: Hairdressers are commonly affected by hand eczema (HE) due to skin hazardous exposure such as irritants and allergens in the work environment. OBJECTIVE: To give an overview of the current prevalence, incidence, and severity, as well as the pattern of debut and the contribution of atopic dermatitis on HE in hairdressers. METHODS: A systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines was performed. Studies published from 2000 to April 2021 that fulfilled predefined eligibility criteria were retrieved. RESULTS: A pooled lifetime prevalence of 38.2% (95% confidence interval [CI] 32.6-43.8), a pooled 1-year prevalence of 20.3% (95% CI 18.0-22.6), and a pooled point prevalence of 7.7% (95% CI 5.8-9.6) of HE was observed in hairdressers. The lifetime prevalence in fully trained hairdressers and hairdressing apprentices was almost identical. The pooled incidence rate of HE was 51.8 cases/1000 person-years (95% CI 42.6-61.0) and the pooled prevalence of atopic dermatitis was 18.1% (95% CI 13.6-22.5). CONCLUSION: HE is common in hairdressers and most hairdressers have debut during apprenticeship. The prevalence of atopic dermatitis in hairdressers is comparable with estimates in the general population, indicating that occupational exposures are the main factor in the increased prevalence of HE in hairdressers. This warrants a strategic and collective effort to prevent HE in hairdressers.

Allergic contact dermatitis caused by 2-hydroxyethyl methacrylate and ethyl cyanoacrylate contained in cosmetic glues among hairdressers and beauticians who perform nail treatments and eyelash extension as well as hair extension applications: A systematic review.

Current cosmetic regulations primarily focus on protecting consumers, not the professional user who is subjected to a partly different, and certainly more intense exposure to hazardous substances. Against this background, this systematic review aims to compile and appraise evidence regarding skin toxicity of 2-hydroxyethyl methacrylate (HEMA; CAS no. 212-782-2) and ethyl cyanoacrylate (ECA; CAS no. 7085-85-0) contained in cosmetic glues used among hairdressers and beauticians who perform nail treatments and eyelash extension as well as hair extension applications. This systematic review followed the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) 2020 recommendations for reporting systematic reviews and meta-analysis. In total, six publications from six countries were eligible for this systematic review. A meta-analysis revealed that hairdressers and beauticians have a ninefold increased risk of developing contact allergy to HEMA compared with controls who are not hairdressers and beauticians. Results for ECA are lacking. The results of this systematic review clearly show that-regarding contact allergy to acrylates-it is not appropriate to apply risk assessment for consumers to hairdressers and beauticians who occupationally handle cosmetic glues. The regulations in existence do not adequately address occupational risks for hairdressers and beauticians connected with the use of acrylate-containing cosmetic substances and need reconsideration.

Differences between hairdressers and consumers in skin exposure to hair cosmetic products: A review.

Hairdressers are at high risk of developing occupational hand eczema. Opinions on the health and safety concerns of nonfood consumer products, such as cosmetics and their ingredients, consider the exposure of a "common consumer," which may not account for occupational exposure of hairdressers. As a result, there is a parlous scenario in which serious safety concerns about occupational exposures are present. The purpose of this review is to compare the frequency of exposure to various types of hair cosmetic products among hairdressers and consumers. Database searches for this review yielded a total of 229 articles; 7 publications were ultimately included. The analysis showed that-dependent on the task-hairdressers were exposed 4 to 78 times more than consumers to a wide spectrum of hair cosmetic products used in their daily working life, ranging from shampoos, conditioners, oxidative and nonoxidative hair colors, to bleaching agents. The highest frequency was found for coloring hair with oxidative hair color. Consumer use frequency does not appear to be appropriate for representing hairdresser exposure. The current standards do not effectively address the occupational risks associated with hairdressers' use of cosmetics. The findings of this study should cause current risk-assessment procedures to be reconsidered.

Guidelines for diagnosis, prevention, and treatment of hand eczema.

BACKGROUND: Hand eczema is a common inflammatory skin disorder. Health care providers need continuously updated information about the management of hand eczema to ensure best treatment for their patients. OBJECTIVES: To update the European Society of Contact Dermatitis guideline on the diagnosis, prevention, and treatment on of hand eczema. METHOD: The Guideline Development Group (GDG) was established on behalf of the ESCD. A call for interest was launched via the ESCD website and via the ESCD members' mailing list. Appraisal of the evidence for therapeutic and preventive interventions was applied and a structured method of developing consensus was used and moderated by an external methodologist. The final guideline was approved by the ESCD executive committee and was in external review on the ESCD webpage for 1 month. RESULTS: Consensus was achieved for several statements and management strategies. CONCLUSION: The updated guideline should improve management of hand eczema.

Treatment with alitretinoin in patients taking part in a tertiary individual prevention program for work-related skin diseases.

BACKGROUND: Patients taking part in a tertiary individual prevention program (TIP) for work-related skin diseases frequently have chronic hand eczema (HE) for which alitretinoin is a treatment option. OBJECTIVE: To investigate treatment with alitretinoin before and during the TIP and related factors. METHODS: Data of 1614 patients taking part in the TIP between January 2015 and December 2019 were analyzed retrospectively. RESULTS: Three hundred forty-eight patients (21.6%) reported treatment with alitretinoin prior to the TIP showing an increase over time, particularly in men. In 45 patients (2.8%), alitretinoin treatment was initiated during the TIP. Treatment with alitretinoin was significantly less common among female than male patients, both prior to (P < .001) and during the TIP (P = .015). Female patients who had received alitretinoin in the past were significantly older than the other female patients (P < .001). Among patients treated with alitretinoin prior to the TIP, women had a significantly higher disease severity at admission than men (P = .007). CONCLUSIONS: About twenty percent of patients reported treatment with alitretinoin prior to the TIP. The data indicate that treatment of female TIP patients with alitretinoin is less frequent than among male patients and depends on age and disease severity.

Stratum corneum levels of inflammatory mediators and natural moisturizing factor in patch test reactions to thiurams and fragrances and their possible role in discrimination between irritant and allergic reactions to hapten mixtures.

BACKGROUND: Patch test (PT) reactions to thiuram mix (TM) and fragrance mix (FM) I or II without concomitant reactions to their single constituents are potentially caused by the irritant properties of the mixes. OBJECTIVE: Comparing inflammatory profiles of PT reactions to TM, FM I, FM II, and their constituents and assessing their potential in discrimination of irritant and allergic reactions. PATIENTS AND METHODS: Levels of 14 cytokines and natural moisturizing factor (NMF) were determined in stratum corneum samples collected from PT reactions to TM, FM I or II, their constituents, and petrolatum (pet.) control sites in 36 individuals. RESULTS: Levels of interleukin (IL)-16, chemokine (CXC motif) ligand (CXCL) 8, CXCL10, chemokine (CC motif) ligand (CCL) 17, and CCL22 were significantly increased in reactions (+, ++) to thiurams and fragrances compared to their petrolatum. controls, except for PT reactions to FM I/II with negative breakdown testing in which, however, decreased levels of NMF were observed. In doubtful reactions to FM I/II with negative breakdown testing, NMF was significantly lower than in petrolatum controls. CONCLUSIONS: PT reactions to thiurams and fragrances indicate a Th2-skewed inflammation. The inflammatory profiles suggest that weak or doubtful FM I/II reactions without accompanying reaction to a constituent were irritant. IL-16 might be suitable to distinguish irritant from allergic reaction.

Incidence rates of occupational contact dermatitis in Denmark between 2007 and 2018: A population-based study.

BACKGROUND: Recent population-based studies on the incidence rates (IRs) of occupational contact dermatitis (OCD) are sparse. OBJECTIVES: To determine the IRs of OCD and development thereof between 2007 and 2018 in known risk occupations. METHODS: Data on all recognized cases of OCD were used to calculate IRs as the number of recognized OCD cases per 10 000 workers per year. Asymptotic chi-square test was used to compare the IRs between 2007-2012 and 2013-2018. RESULTS: The median age at notification of OCD was below 30 years for several of the examined occupations. Hairdressers and beauticians, bakers, dentists and dental assistants, and manufacturing of windmills had the highest overall IRs of OCD. We found a statistically significant increase in the IRs of OCD for child/nursery care workers. CONCLUSIONS: The median age at notification of OCD was low for several of the occupations, signifying the need for further preventive strategies among young people. Based on the IRs of OCD, future preventive efforts should be directed at hairdressers and beauticians, bakers, dentists and dental assistants, and manufacturing of windmills. Furthermore, the statistically significant increase in IRs of OCD among child/nursery care workers highlights the need for further preventive strategies in this field.