[An epidemiological and evolutionary profile of occupational asthma of Tunisian workers]. / Profil épidémiologique et évolutif de l'asthme professionnel des travailleurs tunisiens.

INTRODUCTION: This study aims to identify the epidemiological and occupational characteristics of patients with occupational asthma (OA) and to assess their clinical evolution and occupational outcomes. METHODS: We carried out a descriptive epidemiological study over a period of five years (from 2012 to 2016) about the OA cases in the private sector reported in the Tunisian region of Zaghouan. RESULTS: All in all, 165 OA cases were reported during the study period, representing an annual incidence of 733.3 cases per 1,000,000 workers in the private sector. Our study population was composed predominantly (85.5%) of women, whose mean age was 41.5±6.8years. More than three quarters of the affected persons were working in the automobile industry, and most illnesses (77%) were attributable to isocyanates. The mean time to onset of the respiratory symptoms was longer for low molecular weight agents (13.6±3.1years) compared to high molecular weight agents (12.0±3.9years) (P=0.0006). The majority of OA cases (66.7%) lost their jobs. Job loss was significantly more frequent among asthmatic women and workers with OA due to isocyanates. Among the 62 cases of OA for whom risk factors were eliminated, 45 nonetheless remained symptomatic. CONCLUSION: Effective prevention strategies involving the various actors need to be implemented in work environments so as to reduce the frequency and the medico-legal repercussions of a disabling condition.

Recent developments in occupational asthma.

PURPOSE OF REVIEW: Occupational asthma (OA) is a complex condition that can be difficult to diagnose. The purpose of this review is to describe some recent findings regarding the epidemiology of OA, the occupational sensitizing agents, the prognosis of OA, and its primary prevention. RECENT FINDINGS: The risk of developing OA varies according to the geographic localization of the worker, the type of industry and the type of sensitizing agents. New findings have been reported for several known sensitizing agents, such as isocyanates, seafood & cleaning agents, and their related industries, such as hairdressing salons and schools. Moreover, a few new sensitizing agents, such as cannabis, have been identified in the past few years. The prognosis of OA seems worse than that of nonwork-related asthma. It is mainly determined by the duration and the level of exposure. Primary prevention is crucial to reduce the number of new cases of OA. Complete avoidance of exposure to the causal agent remains the optimal treatment of sensitizer-induced OA. SUMMARY: Improving our knowledge regarding OA and its causative agents is key to enable an early recognition of this condition and improve its prognosis. Further research is still needed to improve primary prevention.

Update on occupational allergy, including asthma, to soluble platinum salts.

PURPOSE OF REVIEW: This review aims to evaluate recent literature on occupational platinum salt exposure and allergy and asthma in the context of existing evidence. RECENT FINDINGS: A major recent development is that large quantitative platinum salt exposure datasets have become available and are finding applications in epidemiological studies. These exposure data are expected to lead to higher quality epidemiological studies focusing on exposure response relations, modifiers of exposure and sensitization risk. The exposure data might also improve medical referral advice as part of medical surveillance studies and contribute to improved evidence on the effectiveness of exposure referral. SUMMARY: Hopefully, the availability of exposure databases form a stimulus for more exposure response studies and risk assessments leading to science based primary prevention approaches. The availability of more detailed exposure data can guide job transfer decisions in occupational clinical practice.

Identification of true chemical respiratory allergens: Current status, limitations and recommendations.

Asthma in the workplace is an important occupational health issue. It comprises various subtypes: occupational asthma (OA; both allergic asthma and irritant-induced asthma) and work-exacerbated asthma (WEA). Current regulatory paradigms for the management of OA are not fit for purpose. There is therefore an important unmet need, for the purposes of both effective human health protection and appropriate and proportionate regulation, that sub-types of work-related asthma can be accurately identified and classified, and that chemical respiratory allergens that drive allergic asthma can be differentiated according to potency. In this article presently available strategies for the diagnosis and characterisation of asthma in the workplace are described and critically evaluated. These include human health studies, clinical investigations and experimental approaches (structure-activity relationships, assessments of chemical reactivity, experimental animal studies and in vitro methods). Each of these approaches has limitations with respect to providing a clear discrimination between OA and WEA, and between allergen-induced and irritant-induced asthma. Against this background the needs for improved characterisation of work-related asthma, in the context of more appropriate regulation is discussed.

Endotypes of occupational asthma.

PURPOSE OF REVIEW: To describe recent findings in endotyping occupational asthma by addressing the role of specific biomarkers. RECENT FINDINGS: Studies on occupational asthma endotypes have focused on immune and inflammatory patterns associated with different occupational exposures to sensitizers or irritants.Sputum neutrophilia has been found in 58.5% patients with occupational asthma caused by high molecular weight (HMW) agents, and work-related dysphonia in patients with occupational asthma was described as associated with sputum neutrophilia too. Neutrophils have been associated also with irritant-induced asthma. The measurement of specific IgE has been confirmed as a valuable diagnostic tool in occupational asthma caused by HMW agents, on the contrary, for most low-molecular-weight agents, the presence of specific IgE has been proven in a small subset of affected workers. Fractional exhaled nitric oxide has been confirmed as a marker of type 2 (T2) inflammation in occupational asthma, mostly when induced by HMW agents (e.g. flour), and it has proved to be more sensitive than spirometry in measuring the efficacy of an intervention.MicroRNA-155 has been shown to contribute to airway inflammation in occupational asthma induced by toluene diisocyanate. SUMMARY: Occupational asthma is heterogeneous, thus monitoring multiple biomarkers is crucial to understand, which inflammatory responses are prevalent.

Long-term outcome of occupational asthma with different etiology.

PURPOSE OF REVIEW: This review summarizes the recent literature on the long-term outcome of sensitizer-induced and irritant-induced occupational asthma. RECENT FINDINGS: Recent studies of sensitizer-induced occupational asthma show that after the offending exposure has ceased, most patients report at least partial relief of symptoms. However, in the long term, the diagnosis may negatively impact their careers, incomes, and quality of life. The studies also offer new insights into diisocyanate-induced occupational asthma phenotypes and asthma remission rates. One third of these cases were in remission in long-term after reduction or cessation of exposure. The long-term prognosis of irritant-induced occupational asthma was demonstrated to be poorer than sensitizer-induced occupational asthma. Older age, low fractional exhaled nitric oxide levels and uncontrolled asthma at the time of diagnosis predicted uncontrolled asthma in the long term in patients with irritant and low-molecular-weight sensitizer induced occupational asthma. SUMMARY: Recent studies provide further evidence of the long-term outcome of different occupational asthma phenotypes and the factors that affect them. These findings help us identify patients at risk of poor asthma outcomes, who need close monitoring and support. It should also be borne in mind that occupational asthma diagnosis may have wider-ranging negative impacts on patients' lives.

Characterization of Relevant Bovine DanderAllergen Components

Background: Diagnostic tests in occupational allergic diseases are highly dependent on the quality of available allergen extracts and specific IgE tests. To enhance diagnostic testing in cattle-related occupational rhinitis, asthma, and urticaria, we produced an in- house cow dander extract, assessed its allergen profile and performance in clinical tests, and compared it with commercial bovine dander extracts. Methods: One hundred patients with a suspected cattle-related occupational disease underwent skin prick tests (SPTs) with in-house and 1 or 2 commercial bovine dander extracts. Nasal allergen provocation tests were performed on 31 patients with suspected occupational rhinitis. We used Western blot to study the specific IgE-protein reactions from the sera of the patients with positive provocation test results and identified allergens from immunoblot bands using tandem mass spectrometry. Results: The odorant-binding protein Bos d OBP, bovine serum albumin (Bos d 6), and the lipocalin (Bos d 2) were identified as the major allergens. We found a total of 24 bovine dander allergens, of which several were formerly unknown. The sensitivity and specificity of the in-house extract in SPTs were 100% and 94%, respectively, in 87 patients. The SPT results were negative in 20 healthy controls. Nasal allergen provocation tests with in-house extract detected occupational rhinitis with 100% sensitivity in 21 patients. The provocation results remained negative in 5 healthy controls. Conclusions: Three major and several minor allergens in bovine dander caused occupational rhinitis. Diagnosis of bovine allergen–related occupational diseases requires a sufficient concentration and variety of tested allergens (AU)

Antecedentes : las pruebas de diagnóstico en enfermedades alérgicas profesionales dependen en gran medida de la calidad de los extractos de alérgenos disponibles y de las pruebas de IgE específicas. Para mejorar las pruebas de diagnóstico en rinitis, asma y urticaria ocupacional relacionadas con el ganado, produjimos un extracto de caspa de vaca internamente, evaluamos su perfil de alérgenos y su desempeño en pruebas clínicas, y lo comparamos con extractos de caspa bovina comerciales. Métodos : Cien pacientes con sospecha de enfermedad profesional relacionada con el ganado se sometieron a pruebas cutáneas (SPT) con extractos de caspa bovina internos y 1 o 2 comerciales. Se realizaron pruebas de provocación con alérgenos nasales a 31 pacientes con sospecha de rinitis ocupacional. Utilizamos Western blot para estudiar las reacciones específicas de la proteína IgE de los sueros de los pacientes con resultados positivos en la prueba de provocación e identificamos alérgenos a partir de bandas de inmunotransferencia mediante espectrometría de masas en tándem.Resultados : La proteína fijadora de olores Bos d OBP, la albúmina sérica bovina (Bos d 6) y la lipocalina (Bos d 2) se identificaron como los principales alérgenos. Encontramos un total de 24 alérgenos de la caspa bovina, de los cuales varios eran desconocidos hasta el momento. La sensibilidad y especificidad del extracto interno en los SPT fueron del 100% y 94%, respectivamente, en 87 pacientes. Los resultados del SPT fueron negativos en 20 controles sanos. Las pruebas de provocación de alérgenos nasales con extracto interno detectaron rinitis ocupacional con una sensibilidad del 100% en 21 pacientes. Los resultados de la provocación siguieron siendo negativos en 5 controles sanos(AU)

Fatal Occupational Asthma in Cannabis Production - Massachusetts, 2022.

Multiple respiratory hazards have been identified in the cannabis cultivation and production industry, in which occupational asthma and work-related exacerbation of preexisting asthma have been reported. An employee working in a Massachusetts cannabis cultivation and processing facility experienced progressively worsening work-associated respiratory symptoms, which culminated in a fatal asthma attack in January 2022. This report represents findings of an Occupational Safety and Health Administration inspection, which included a worksite exposure assessment, coworker and next-of-kin interviews, medical record reviews, and collaboration with the Massachusetts Department of Public Health. Respiratory tract or skin symptoms were reported by four of 10 coworkers with similar job duties. Prevention is best achieved through a multifaceted approach, including controlling asthmagen exposures, such as cannabis dust, providing worker training, and conducting medical monitoring for occupational allergy. Evaluation of workers with new-onset or worsening asthma is essential, along with prompt diagnosis and medical management, which might include cessation of work and workers' compensation when relation to work exposures is identified. It is important to recognize that work in cannabis production is potentially causative.

Occupational asthma induced by fish exposure.

Occupational asthma triggered by inhaling fish-derived aerosols is estimated to affect 2-8% of exposed individuals. This primarily affects workers in the fish processing industry. Fishmongers, rarely experience this issue, as recent research found no significant difference in asthma rates compared to a control group. We report the case of a fishmonger who presented with a 1-year history of rhinoconjunctivitis and asthma. The patient attributed these symptoms to his occupational exposure within the fish market environment, which worsened in the cold storage warehouse. Symptoms improved during holidays. Diagnosis involved skin-prick tests, sIgE (ImmunoCAP-specific IgE) measurements, and bronchial challenge tests, confirming occupational asthma from fish bioaerosol exposure. Parvalbumins, common fish proteins, share structural similarities, leading to cross-reactivity in fish allergy sufferers. In this case, sensitivity to rGad c1 (cod parvalbumin) was identified as the primary trigger for the patient's asthma, and responsible for sensitizations observed across various tested fish species.

Disposition of Work-Related Asthma in a Spanish Asthma Cohort: Comparison of Asthma Severity Between Employed and Retired Workers.

BACKGROUND: Exposure to certain agents in the workplace can trigger occupational asthma or work-exacerbated asthma, both of which come under the heading of work-related asthma (WRA). Understanding the burden that WRA represents can help in the management of these patients. OBJECTIVE: To assess the influence of occupation on asthma in real life and analyze the characteristics of patients with WRA included in an asthma cohort. METHODS: This was a prospective multicenter study of a cohort of consecutive patients with asthma. A standardized clinical history was completed. Patients were classified as having WRA or non-WRA. All patients underwent respiratory function tests, FeNO test, and methacholine challenge (methacholine concentration that causes a 20% drop in FEV1) at the beginning of the study. They were classified into two groups, depending on their employment status: employed (group 1) or unemployed (group 2). RESULTS: Of the 480 patients included in the cohort, 82 (17%) received the diagnosis of WRA. Fifty-seven patients (70%) were still working. Mean age (SD) was 46 (10.69) years in group 1 and 57 (9.91) years in group 2 (P < .0001). Significant differences were observed in adherence to treatment (64.9% in group 1 vs 88% in group 2; P = .0354) and in severe asthma exacerbations (35.7% in group 1 vs 0% in group 2; P = .0172). No significant differences were observed in the rest of the variables analyzed. CONCLUSIONS: The burden of WRA in specialized asthma units is not negligible. The absence of differences in the severity of asthma, the treatment administered, alterations in lung function, and the number of exacerbations in those working versus not working may support the idea that advice regarding changing jobs should be customized for individual patients.

Serial fractional exhaled nitric oxide measurements at and off work may help to identify immunologic occupational asthma in cases with complex exposures.

Serial measurements of fractional exhaled nitric oxide (FeNO) at home and at work have been described to provide complementary information for the diagnosis of occupational asthma (OA) when specific inhalation challenge (SIC) is missing or doubtful. We describe two cases in which serial FeNO measurements enabled the detection of probable OA after complex exposures. A 25-year-old industrial painter with exposure to a variety of paints suffered from work-related airway symptoms for five years. Lung function was normal, and she was not atopic. SIC with hexamethylene diisocyanate was negative. A 47-year-old sign maker (screen printing, foils) suffering from work-related dyspnoea for seven years. Moderate airway obstruction, but no atopy was detectable. Due to the complex exposures SIC was not performed. Both patients performed FeNO measurements once daily during a 2-week-holiday and a subsequent 2-week-work period. In both cases elevated baseline FeNO decreased to normal (25 ppb) during holidays and increased after resuming work (case 1: 125 ppb, case 2: 45 ppb).

[Allergy and immunotoxicology in preventive and clinical medicine from theory to practice: Occupational allergy and isocyanate-induced asthma].

Genetic and environmental factors and their interactions cause diseases and deteriorate health (Genetic and Environmental Interaction). Exposure to environmental factors plays a major role in the deterioration of health in the workplace.Occupational asthma (OA) is a common disorder in the workplace. Approaches to OA are well described and discussed in "Japanese Guideline for Diagnosis and Management of Occupational Allergic Diseases" by the Japanese Society of Occupational and Environmental Allergy. According to the guideline, OA and work-aggravated asthma comprise work-related asthma, and OA can be further divided into two disease entities: sensitizer-induced OA and irritant-induced OA. The guidelines also describe diagnostic and therapeutic strategies for OA. Since a definitive diagnosis of OA requires a comprehensive decision based on a detailed interview on clinical symptoms related to employment status and clinical tests, including inhalation tests of suspected substances as needed, the possibility of OA should be considered as the first step toward diagnosis of the patient. Otherwise, OA may not be diagnosed. Therapeutic strategies include exposure avoidance, environmental arrangements in the workplace, utilization of social resources for workers, and conventional pharmacotherapy for asthma.Artificially synthesized small compounds are used in various industries and can cause allergies. For example, isocyanates are small compounds in the -NCO group, which have been toxicologically studied. It was later shown that isocyanate could cause various nontoxic adverse health effects, including allergic reactions. Since small agents with low molecular weights bind to proteins, detecting their specific immunoglobulin E (IgE) antibodies targeting small compounds is generally difficult. In contrast, isocyanate-specific IgE antibodies are detectable in individuals with isocyanate allergies.Suspecting OA is essential in cases exposed to newly synthesized compounds, or to those that are already known but applied to new uses, which can be better understood and predicted by studying the health effects of isocyanates.Academic interest in various issues related to allergies, immunology, and toxicology in the workplace includes clinical medicine, epidemiology, and epigenetics related to environmental exposure. Further advanced research in these areas is necessary and promising.

Long-Term Outcome of Occupational Asthma From Irritants and Low-Molecular-Weight Sensitizers.

BACKGROUND: The short-term asthma outcome of irritant-induced asthma (IIA) is poorer than that of low-molecular-weight (LMW) sensitizer-induced occupational asthma (OA). OBJECTIVES: To evaluate the long-term asthma outcome of IIA and LMW-induced OA and to determine which baseline features are associated with a poor long-term outcome. METHODS: This follow-up questionnaire study assessed 43 patients diagnosed with IIA and 43 patients with LMW-induced OA at the Finnish Institute of Occupational Health in 2004-2018. The baseline results were analyzed to detect features associated with uncontrolled asthma (Asthma Control Test [ACT] score of ≤19, or ≥2 exacerbations or ≥1 serious exacerbation within 1 year) at follow-up. RESULTS: The median interval since OA diagnosis was 6.3 years (interquartile range [IQR]: 4.4-11.3 years). Uncontrolled asthma was more frequent with IIA than with LMW-induced OA (58% vs 40%, adjusted odds ratio [OR]: 3.60, 95% confidence interval [CI]: 1.20-10.81). Poor symptom control was the main factor for this difference (median [IQR] ACT score of 18 [15-22] vs 21 [18-23], P = .036, respectively). Among all participants, older age (OR: 1.08 per year, 95% CI: 1.02-1.15), a fractional exhaled nitric oxide (FeNO) value <20 ppb (OR: 5.08, 95% CI: 1.45-17.80), and uncontrolled asthma at baseline (OR: 3.94, 95% CI: 1.31-11.88) were associated with uncontrolled asthma at follow-up. CONCLUSIONS: Long-term asthma control of IIA appears to be inferior to that of LMW-induced OA. Older age, a low FeNO value, and uncontrolled asthma at baseline might indicate a worse long-term outcome among those with IIA and LMW-induced OA.

Occupational asthma, rhinitis and contact urticaria in a salmon-processing worker.

We report a case of occupational allergy to salmon combining allergic asthma, allergic rhinitis and allergic contact urticaria in a 59-year-old salmon-processing worker. Parvalbumin is the most common allergen, but indeed sensitisation to tropomyosin, preservatives and spices could occur.

Screening tools for work-related asthma and their diagnostic accuracy: a systematic review protocol.

INTRODUCTION: Work-related asthma (WRA) refers to asthma caused by exposures at work (occupational asthma) and asthma made worse by work conditions (work-exacerbated asthma). WRA is common among working-age adults with asthma and impacts individual health, work-life and income but is often not detected by healthcare services. Earlier identification can lead to better health and employment outcomes. However, the optimal tool for screening and its effectiveness in practice is not well established. Screening tools may include whole questionnaires, questionnaire items, physiological measurements and/or immunological tests. Since the publication of the most contemporary WRA or occupational asthma-specific guidelines, further studies evaluating tools for identifying WRA have been performed. Our systematic review aims to summarise and compare the performance of screening tools for identifying WRA in both clinical and workplace settings. METHODS AND ANALYSIS: We will conduct a systematic review of observational and experimental studies (1975-2021) using MEDLINE, EMBASE, CINAHL Plus, Web of Science, CDSR, DARE, HTA, CISDOC databases and grey literature. Two independent reviewers will screen the studies using predetermined criteria, extract data according to a schedule and assess study quality using the Quality Assessment of Diagnostic Test Accuracy 2 tool. Screening tools and test accuracy measures will be summarised. Paired forest plots and summary receiver operating characteristic curves of sensitivities and specificities will be evaluated for heterogeneity between studies, using subgroup analyses, where possible. If the studies are sufficiently homogenous, we will use a bivariate random effect model for meta-analysis. A narrative summary and interpretation will be provided if meta-analysis is not appropriate. ETHICS AND DISSEMINATION: As this is a systematic review and does not involve primary data collection, formal ethical review is not required. We will disseminate our findings through open access peer-reviewed publication as well as through other academic and social media. PROSPERO REGISTRATION NUMBER: CRD42021246031.

Prevalence of work-related asthma among Egyptian farmers in Great Cairo.

Work related asthma (WRA) refers to asthma induced by exposure to sensitizing agents and/or irritants in the workplace leaving health and economic consequences. Early diagnosis can improve the prognosis of WRA permitting sometimes full recovery. This study aimed to assess the prevalence of WRA among Egyptian adult agriculture workers. A multi-center cross sectional study included 150 adult workers from 4 different farms, during the period from 2019 and 2021. All participants were subjected to full medical history, clinical examination, chest x-ray, skin prick test and CBC to detect absolute eosinophilic count. Spirometry with post bronchodilatation test (reversibility test) at the farm (in the day of insecticide aerosol and without aerosol) and after a week off the farm was also done. Age, median ± SD, was 37.67 ± 9.75 years, duration of farming occupation was 21.84 ± 10.18 years. Of the 150 participants, 11 had WRA. Of these, 6 had allergic occupational asthma, 3/11 had work exacerbated asthma and only 2/11 had irritant occupational asthma. Of the allergic subjects, 7.3% tested positive to mixed pollens, 4.7% to Alternaria, 2% to penicillium and 2% to the farm pollens. The onset of respiratory symptoms was 13.45 ± 6.93 months after start working in the farm. A statistical significance was observed between WRA and non-WRA individuals regarding age, duration of farming occupation and asthma symptoms during workday (P < 0.001). There was a statistical significance between WRA group and non-WRA group regarding FEV1, FEV1/FVC ratio carried out at work, during holidays and during spraying (P < 0.001). Absolute eosinophilic count, mean among WRA group was 0.55 ± 0.13 (×103cells/mm3) with significance between WRA and non-WRA (P= 0.001). Farming occupation may cause WRA, therefore, more attention should be given to minimize exposure and risk of inducing WRA.