Diagnosis and frequency of work-exacerbated asthma among bakers

Occupational Asthma Caused by Low-Molecular-Weight Chemicals Associated With Contact Dermatitis: A Retrospective Study

BACKGROUND

Occupational asthma (OA) may have different etiologies, but it is not clear whether the etiologic agents influence the clinical presentation, especially the co-occurrence of skin lesions.

OBJECTIVE

To determine the impact of different asthmagens on the characteristics of OA, with a focus on the occurrence of prior or concomitant skin disorders.

METHODS

In a retrospective analysis of patients who visited the Occupational and Environmental Disease Clinic of a tertiary referral hospital from 2009 to 2019, we classified patients into definite, probable, or possible OA according to prespecified diagnostic guidelines. In multivariate logistic regression with sensitivity analysis, we examined the relation of high- and low-molecular-weight (HMW and LMW) agents with the clinical presentation.

RESULTS

Of 209 cases of OA, 66 were caused by HMW agents and 143 by LMW agents. Patients with OA exposed to LMW agents had higher odds of having (had) allergic contact dermatitis (odds ratio, 5.45 [1.80-23.70]; P < .01), compared with patients exposed to HMW agents. Conversely, HMW agents were associated with higher odds of rhinitis symptoms (odds ratio of LMW/HMW, 0.33 [0.17-0.63]; P < .001) and high total IgE (odds ratio of LMW/HMW, 0.35 [0.17-0.70]; P < .01). Risk factors for having coexisting contact dermatitis included construction work, hairdressing, and exposure to metals or epoxy resins.

CONCLUSIONS

Among patients with OA, exposure to specific LMW agents was associated with a high frequency of contact dermatitis. Different types of asthmagens within HMW or LMW agents appear to determine the phenotype and comorbidity of OA.

Dietary Management of Food Allergy

Worldwide food allergy prevalence is increasing, especially in children. Food allergy management strategies include appropriate avoidance measures and identifying suitable alternatives for a nutritionally sound diet. Individualized dietary intervention begins teaching label reading, which differs among countries or regions. Dietary intervention must result in a nutritionally sound plan including alternatives to support optimal growth and development. Inappropriate or incomplete dietary advice may increase the risk of adverse reactions, growth faltering, and nutrient deficiencies. Evidence indicates input from a registered dietitian improves nutritional outcomes. Nutritional input plays a critical role managing nutritional disorders related to food allergy.

Heat Stress-Related Symptoms among Bakery Workers in Lebanon: A National Cross-Sectional Study

Heat exposure is linked to a range of heat-related illnesses and injuries. This study assessed the association between workers’ perceptions of the work environment and reports of heat stress-related health symptoms in bakery workers in Lebanon. A national cross-sectional survey of workers was carried out in 504 bakeries in Lebanon. One worker in each bakery was interviewed using questions relating to the workplace environment and heat stress-related health symptoms. Heat and humidity measurements were recorded in bakeries. Descriptive analyses were performed, and logistic regression assessed relationships between the workplace environment, worker perceptions, and reports of heat stress-related health symptoms. In total, 47.2% of workers experienced heat stress-related symptoms, 83% perceived workplace temperatures as hot, and 48% perceived these temperatures as affecting their health. Humidex readings showed that 49% of bakeries had conditions unsafe for routine work tasks. Working under pressure (AOR = 1.65; 95% CI = 1.12-2.43), job dissatisfaction (AOR = 1.76; 95% CI = 1.12-2.79), and perceptions that high temperatures negatively affected health (AOR = 2.73; 95% CI = 1.87-3.99) were all significantly correlated to reports of heat stress-related symptoms. Females were more likely to experience heat stress-related symptoms (AOR = 1.96; 95% CI = 1.13-3.39). Workers who reported low levels of water consumption at work were also more likely to experience heat stress-related health symptoms. We conclude that heat exposure potentially impacts workers’ health in Lebanese bakeries. Improvements in workplace conditions, adequate infrastructure, and workers’ training are key interventions for maintaining workers’ health.

Assessment of the Level of Organic Dust and Mould Spores in the Work Environment of Baker

Aim:

This study was conducted to determine the level of fungal contamination of the air in bakeries to assess health hazards for workers.

Materials and Methods:

Six bakeries producing traditionally baked goods were selected for the study. After a background survey, samples of exhaled air were collected to test for fungal aerosols. The inhalable and respirable fraction in the bakery air environment was measured by the gravimetric method.

Statistical Analysis Used:

All data analyses were performed using Statistica software (v 8.0).

Results:

The mean concentration of fungi and particles in the bakeries did not exceed the recommended levels. The air in the bakeries had a low level of microbial contamination. The identified fungi included biological agents from hazard group 2.

Conclusions:

Proper employee training and the introduction of preventive measures (including both individual and group protection) can significantly reduce employees’ exposure and thus their occupational risk.

Occupational Exposure to Flour Dust. Exposure Assessment and Effectiveness of Control Measures

The adverse effects associated with exposure to flour dust have been known since the 1700s. The aim of the study was to assess the occupational exposure to flour dust in Italian facilities, identify the activities characterized by the highest exposure, and provide information to reduce workers’ exposure. The study was performed in different facilities such as flourmills (n = 2), confectioneries (n = 2), bakeries (n = 24), and pizzerias (n = 2). Inhalable flour dust was assessed by personal and area samplings (n = 250) using IOM (Institute of Occupational Medicine) samplers. The results showed personal occupational exposure to flour dust over the American Conference of Governmental Industrial Hygiene (ACGIH) and the Scientific Committee on Occupational Exposure Limit (SCOEL) occupational limits (mean 1.987 mg/m³; range 0.093–14.055 mg/m³). The levels were significantly higher for dough makers in comparison to the dough formers and packaging area subjects. In four bakeries the industrial hygiene surveys were re-performed after some control measures, such as installation of a sleeve to the end of pipeline, a lid on the mixer tub or local exhaust ventilation system, were installed. The exposure levels were significantly lower than those measured before the introduction of control measures. The exposure level reduction was observed not only in the dough making area but also in all bakeries locals.

Occupational Rhinitis

There is convincing evidence that tight relationships between the upper and lower airways also apply to the workplace context. Most patients with occupational asthma (OA) also suffer from occupational rhinitis (OR), although OR is 2 to 3 times more common than OA. OR most often precedes the development of OA, especially when high-molecular-weight protein agents are involved, and longitudinal cohort studies have confirmed that OR is associated with an increased risk for the development of OA. The level of exposure to sensitizing agents at the workplace is the most important determinant for the development of IgE-mediated sensitization and OR. Atopy is a risk factor for the development of IgE-mediated sensitization only to high-molecular-weight agents. In workers with work-related rhinitis symptoms, documentation of IgE-mediated sensitization to a workplace agent via skin prick testing or serum specific IgE confirms a diagnosis of probable OR, whereas specific nasal provocation testing in the laboratory remains the reference method to establish a definite diagnosis of OR. Complete avoidance of exposure to the causal agent is the most effective therapeutic option for controlling work-related nasal symptoms and preventing the development of OA. If complete elimination of exposure is expected to induce meaningful adverse socioeconomic consequences, reduction of exposure can be considered as an alternative approach, but it is important to consider the individual risk factors for the development of OA to implement a more personalized management of OR.

Occupational Exposures to Organic Dust in Irish Bakeries and a Pizzeria Restaurant

For decades, occupational exposure to flour dust has been linked to a range of respiratory diseases, including occupational asthma, thought to result from exposure to fungi present in the flour. Antifungal resistance is of increasing prevalence in clinical settings, and the role of occupational and environmental exposures, particularly for specific fungal species, is of concern. Occupational exposure to flour dust can occur in a range of occupational settings, however, few studies have focused on restaurant workers. The objective of this study was to measure occupational exposure to flour and microbial contamination, including azole resistance screening, in two small commercial bakeries and in a pizzeria. Personal full shift inhalable dust measurements were collected from workers, and were analyzed for inhalable dust and fungi, bacteria, azole resistance, and mycotoxins. Samples of settled dust were collected, and electrostatic dust cloths (EDC) were deployed and analyzed for microbial contamination, including azole resistance screening, and mycotoxins. Geometric mean exposures of 6.5 mg m^-³ were calculated for inhalable dust, however, exposures of up to 18.30 mg m^-³ were measured-70% of personal exposure measurements exceeded the occupational exposure limit for flour dust of 1.0 mg m^-³. The air and EDC fungal counts were similar to those reported in previous studies for similar occupational environments. The fungi were dominated by Penicillium genera, however Aspergillus genera, including Fumigati and Flavi sections, were observed using culture-based methods, and the Fumigati section was also observed by molecular tools. Both Aspergillus sections were identified on the azole resistance screening. Mycotoxins were also detected in the settled dust samples, dominated by deoxynivalenol (DON). The role of environmental exposure in both the development of antimicrobial resistance and the total mycotoxin body burden is a growing concern; therefore, the presence of azole-resistant fungi and mycotoxin contamination, although low in magnitude, is of concern and warrants further investigation.

Transforming growth factor-β1 and eosinophil-derived neurotoxins contribute to the development of work-related respiratory symptoms in bakery workers

Background

In baker's asthma previous studies suggest that adaptive and innate immunity are involved in the development of work-related respiratory symptoms (WRS), where we hypothesized that epithelial cells derive airway inflammation through modulating the release of inflammatory cytokines. Thus, we conducted this study to investigate the role of epithelial cell-derived cytokines in the development of WRS among bakery workers.

Methods

We recruited 385 wheat-exposed subjects with WRS (WRS+)/without WRS (WRS-) working in a single industry and 243 unexposed controls from Ajou Medical Center (Suwon, South Korea). Levels of epithelial cell-derived cytokines (interleukin [IL-8], transforming growth factor-β1 [TGF-β1], eotaxin-2) and inflammatory mediators (eosinophil-derived neurotoxins [EDN]) in sera or cell-free supernatants were measured by ELISA. Human airway epithelial cells (HAECs), A549, were stimulated by wheat flour extracts and co-cultured with peripheral blood neutrophils isolated from 4 asthmatic patients.

Results

Serum TGF-β1 levels were significantly lower in exposed subjects than in unexposed controls, in the WRS+ group than in the WRS- group (P < 0.001 for each). The WRS+ group had a significantly higher level of serum EDN than the WRS- group (P < 0.001). Serum TGF-β1 and EDN levels predicted the development of WRS in exposed subjects (area under the curve [AUC] = 0.719, 72.4% sensitivity/70% specificity; AUC = 0.759, 78.6% sensitivity/60% specificity). From wheat-stimulated HAECs, TGF-β1 release peaked at 6 hours after wheat exposure, while eotaxin-2 peaked at 12 hours. Co-culture of HAECs with neutrophils did not affect TGF-β1 release.

Conclusions

Our results suggest that TGF-β1 may contribute to develop type-2 airway inflammation and WRS. Serum TGF-β1/EDN levels may be potential serum biomarkers for predicting WRS among bakery workers.

Food processing and occupational respiratory allergy- An EAACI position paper

Occupational exposure to foods is responsible for up to 25% of cases of occupational asthma and rhinitis. Animal and vegetable high-molecular-weight proteins present in aerosolized foods during food processing, additives, preservatives, antioxidants, and food contaminants are the main inhalant allergen sources. Most agents typically cause IgE-mediated allergic reactions, causing a distinct form of food allergy (Class 3 food allergy). The allergenicity of a food protein, allergen exposure levels, and atopy are important risk factors. Diagnosis relies on a thorough medical and occupational history, functional assessment, assessment of sensitization, including component-resolved diagnostics where appropriate, and in selected cases specific inhalation tests. Exposure assessment, including allergen determination, is a cornerstone for establishing preventive measures. Management includes allergen exposure avoidance or reduction (second best option), pharmacological treatment, assessment of impairment, and worker's compensation. Further studies are needed to identify and characterize major food allergens and define occupational exposure limits, evaluate the relative contribution of respiratory versus cutaneous sensitization to food antigens, evaluate the role of raw versus cooked food in influencing risk, and define the absolute or relative contraindication of patients with ingestion-related food allergy, pollinosis, or oral allergy syndrome continuing to work with exposure to aerosolized food allergens.

Occupational rhinitis and occupational asthma: Association or progression?

BACKGROUND

Occupational asthma is the most frequently reported occupational respiratory disease in registries, and is often co-diagnosed with occupational rhinitis. We undertook a systematic review of the English-language epidemiologic literature linking these two conditions, with emphasis on progression from occupational rhinitis to occupational asthma.

METHODS

PubMed and Embase were queried in a series of structured searches designed to identify studies comparing occupational asthma and occupational rhinitis incidence or prevalence in occupationally exposed individuals.

RESULTS

The searches yielded a total of 109 unique citations, 15 of which yielded inferential data on the occupational rhinitis-asthma relationship. Nine of fifteen studies showed statistically significant associations between the occurrence of occupational rhinitis and occupational asthma among individual workers.

CONCLUSIONS

Limited data support the notion that occupational rhinitis precedes the development of occupational asthma, particularly when high-molecular-weight (HMW) agents are involved. The relationship between the two conditions could not be evaluated in many relevant studies due to a lack of cross-tabulation of individual cases.

Usefulness of Biomarkers in Work-Related Airway Disease

Determination of biomarkers may be useful in the surveillance of occupational exposure and workers' health. The possibility of predicting development/clinical course of specific disorders or current disease, diagnosing in early steps, and health condition monitoring is a real necessity. Various agents present in the workplace environment (or their metabolites) can be measured in samples possessed from human body (blood and urine, saliva, etc.). On the other hand, inhalant exposure may induce specific or non-specific, local or systemic, acute or chronic biological response expressed by synthesis or releasing specific or non-specific substances/mediators that also can be determined in blood, nasal and bronchial lavage or sputum, tear fluid, exhaled breath, etc. The least is known about genetic markers which may predict individual susceptibility to develop some work-related disorders under the influence of occupational exposure. Due to common exposure to inhalant agents at workplace, researches on biomarkers that allow to inspect the impact of exposure to humans' health are still needed. The authors of this article summarize the utility of biomarkers' determination in work-related airway diseases in a recent clinical approach.

Association of MBL With Work-Related Respiratory Symptoms in Bakery Workers

Baker's asthma is the most prevalent occupational asthma, and IgE-mediated response is known as a major pathogenesis. However, recent studies have suggested the involvement of innate immune response because wheat flour contains bacterial endotoxins or lipopolysaccharides. To further understand a role of innate immune response in the development of work-related respiratory symptoms (WRS) in bakery workers, we investigated mannose-binding lectin (MBL), one of the initiating components of the complement cascade in a single cohort of bakery workers. A total of 373 bakery workers completed a questionnaire regarding WRS. The bakery workers were divided into 2 groups according to previous history of allergic rhinitis (AR)/bronchial asthma (BA): those with history of AR/BA (group I) and those without (group II). We measured serum MBL levels by using enzyme-linked immunosorbant assay and genotyped 4 single nucleotide polymorphisms of the MBL2 gene (226G>A in exon 1, -554G>C, -431A>C, and -225G>C in the promoter) by using TaqMan assays. Fifty-nine subjects (15.5%) were previously diagnosed with AR/BA, and 64 subjects (16.8%) complained of WRS. No significant differences were found in serum MBL levels between groups I and II. However, in group II subjects, but not in group I subjects, the serum MBL levels were significantly higher in bakery workers with WRS than in those without. In addition, the serum MBL levels were significantly different according to genetic polymorphisms of the MBL2 gene and its haplotypes. In conclusion, serum MBL, affected by genetic polymorphisms, may be associated with WRS in bakery workers with no previous history of AR/BA.

Exposure to flour dust in the occupational environment

Exposure to flour dust can be found in the food industry and animal feed production. It may result in various adverse health outcomes from conjunctivitis to baker's asthma. In this paper, flour dust exposure in the above-mentioned occupational environments is characterized and its health effects are discussed. A peer-reviewed literature search was carried out and all available published materials were included if they provided information on the above-mentioned elements. The hitherto conducted studies show that different components of flour dust like enzymes, proteins and baker's additives can cause both non-allergic and allergic reactions among exposed workers. Moreover, the problem of exposure to cereal allergens present in flour dust can also be a concern for bakers' family members. Appreciating the importance of all these issues, the exposure assessment methods, hygienic standards and preventive measures are also addressed in this paper.

Local allergic rhinitis: mechanisms, diagnosis and relevance for occupational rhinitis

PURPOSE OF REVIEW

Local allergic rhinitis (LAR) is a new form of allergic rhinitis that has caused a growing interest. The possibility of an occupational equivalent (occupational rhinitis) has not been yet explored. The purpose of this review is to summarize the most relevant and recent scientific evidence on LAR and occupational rhinitis.

RECENT FINDINGS

LAR is a prevalent entity well differentiated from allergic rhinitis, affecting patients from different countries, ethnic groups and ages. Occupational rhinitis appears earlier and more frequently than occupational asthma, especially for high molecular weight substances. Diagnosis of LAR is based on nasal allergen provocation test and/or detection of nasal specific IgE, and other techniques such as basophil activation test may support the diagnosis. Skin prick tests and immunological determinations are of limited use for diagnosis of occupational rhinitis caused by low molecular weight agents. Performance of nasal allergen provocation test for confirming diagnosis of occupational rhinitis is strongly recommended. Uncommon allergens should also be investigated.

SUMMARY

The possibility of a local occupational rhinitis should be considered in workers with a clear history of occupational rhinitis and negative immunological test, especially in the case of high molecular weight allergens.