Definitions and classification of work-related asthma

Work-related asthma in adults with severe asthma from the Korean Severe Asthma Registry (KoSAR)

Background

Exposure to allergens or irritants in the workplace may affect asthma control and the quality of life (QoL) of patients with asthma.

Objective

To examine the prevalence and characteristics of work-related asthma (WRA) in adult patients with severe asthma.

Methods

We analyzed data from the Korean Severe Asthma Registry (KoSAR), which is a nationwide multicenter observational study on severe asthma in Korea. Severe asthma was defined according to the American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines. WRA was identified on the basis of asthma symptom aggravation at the workplace, as indicated by responses to a structured questionnaire. We compared the demographic and clinical characteristics and QoL between adult patients with severe asthma and WRA and those without WRA.

Results

Among 364 patients with severe asthma who were employed at the time of enrollment, 65 (17.9%) had WRA. There were no significant differences in age, sex, obesity, or smoking history between the WRA and non-WRA groups. However, individuals with WRA exhibited a higher prevalence of anxiety (7.7% vs 2.4%, P = 0.046) and depression (12.3% vs 3.7%, P = 0.010) than those without. The levels of asthma control, lung function, and frequency of asthma exacerbations were similar between the two groups, but patients with WRA reported lower QoL, as determined by the Quality of Life Questionnaire for Adult Korean Asthmatics (56.6 ± 14.6 vs. 63.5 ± 13.9, P < 0.001).

Conclusion

Patients with severe asthma and WRA are more likely to experience anxiety and depression and have lower QoL than those without WRA.

Ent Manifestations in Sculptors of South Chennai, India: A Cross Sectional Observational Study

Despite the National Occupational Safety and Legislation Act 2020's implementation, reports of workplace accidents are rising in India. Various ear, nose, and throat conditions have been linked to a wide range of physico-chemical variables. Due to a lack of training, inadequate knowledge, a lack of awareness of occupational health and safety risks, or a lack of accessibility to or use of personal protective equipment (PPE), sculptors are frequently exposed to a variety of physical, compound and unplanned risks, chemical, and accidental hazards. The study aimed to assess the various ear, nose and throat manifestations like noise induced hearing loss, occupational rhinitis and non-infectious pharyngitis among the sculptors working in the southern part of Chennai. This observational study was performed in a total of 110 sculptors. Demographic data like age, education, duration of occupation, use of PPE like face mask, ear plug during work hours, whether sculpting is a family occupation or first generation sculptor. A detailed history and thorough ENT examination was performed with pure tone audiometry (PTA), diagnostic nasal endoscopy (DNE) and videolaryngoscopy (VLS). If any problem is detected they will be treated accordingly. Most of them (70%) were in the age group of 21-40 years but 71% of them are sculptors for more than 15 years which infers introduction to the occupation at an early age. The reason for this could be more than 80% of them possessed the heritage of sculpting as their family occupation. Duration of occupation was significantly associated with chronic rhinitis (P value was 0.002) and NIHL (P value was 0.002) whereas education and use of PPE like face mask or ear plugs were not associated with ENT manifestations. This study focuses on the sculptors' working habits, their ignorance of safety precautions, and an assessment of the numerous ENT ailments. These manifestations showed a strong correlation to exposure time. To prevent the issues from becoming more severe, regular medical monitoring is required for early detection and intervention.

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.

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.

Association of individual green space exposure with the incidence of asthma and allergic rhinitis: a systematic review and meta-analysis

The association between allergic respiratory diseases, such as asthma and allergic rhinitis (AR), and green space (GS) remains controversial. Our study aimed to summarize and synthesize the association between individual GS exposure and the incidence of asthma/AR. We systematically summarized the qualitative relationship between GS exposure and asthma and AR. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was used to estimate the effect of the Normalized Difference Vegetation Index (NDVI) on asthma and AR. A total of 21 studies were included for systematic review, and 8 of them underwent meta-analysis. In the meta-analysis of current asthma, the 0 < radius ≤ 100 m group, 100 < radius ≤ 300 m group, and 500 < radius ≤ 1000 m group presented weak negative associations between the NDVI and current asthma. For ever asthma, slight positive associations existed in the 0 < radius ≤ 100 m group and 300 < radius ≤ 500 m group. In addition, the NDVI might slightly reduce the risk of AR in radius of 100 m and 500 m. Our findings suggest that the effects of GS exposure on asthma and AR were not significant. Differences in GS measurements, disease diagnoses and adjusted confounders across studies may have an impact on the results. Subsequent studies should consider potential confounding factors and use more accurate GS exposure measurements to better understand the impact of GS exposure on respiratory disease in the population.

Clinical Characteristics of Irritant-Induced Occupational Asthma

BACKGROUND

Work is a substantial contributing factor of adult-onset asthma. A subtype of occupational asthma (OA) is caused by irritant agents, but knowledge of the clinical outcomes of irritant-induced asthma (IIA) is incomplete.

OBJECTIVES

To evaluate whether the clinical picture of IIA differs from that of sensitizer-induced OA.

METHODS

This retrospective study analyzed acute and subacute IIA patients diagnosed in an occupational medicine clinic during 2004 to 2018. Sixty-nine patients fulfilled the inclusion criteria, and their characteristics were analyzed at the time of the diagnosis and 6 months later. The results were compared with those of 2 subgroups of sensitizer-induced OA: 69 high-molecular-weight (HMW) and 89 low-molecular-weight (LMW) agent-induced OA patients.

RESULTS

Six months after the diagnosis, 30% of the patients with IIA needed daily short-acting β-agonists (SABA), 68% were treated with Global Initiative for Asthma, 2020 report (GINA) step 4-5 medication, and 24% of the patients had asthma exacerbation after the first appointment. IIA depicted inferiority to LMW-induced OA in daily need for SABA (odds ratio [OR]: 3.80, 95% confidence interval [CI]: 1.38-10.46), treatment with GINA step 4-5 medication (OR: 2.22, 95% CI: 1.08-4.57), and exacerbation (OR: 3.85, 95% CI: 1.35-11.04). IIA showed poorer results than HMW-induced OA in the latter 2 of these features (OR: 2.49, 95% CI: 1.07-5.79 and OR: 6.29, 95% CI: 1.53-25.83, respectively).

CONCLUSIONS

Six months after the OA diagnosis, a significant proportion of the patients with IIA remain symptomatic and the majority of these patients use asthma medications extensively suggesting uncontrolled asthma. The short-term outcomes of IIA appear poorer than that of sensitizer-induced OA.

Work-related asthma

Work-related asthma (WRA) is highly prevalent in the adult population. WRA includes occupational asthma (OA), which is asthma caused by workplace exposures, and work-exacerbated asthma (WEA), also known as work-aggravated asthma, which is preexisting or concurrent asthma worsened by workplace conditions. In adults, the estimated prevalence of OA is 16.0%, whereas that of WEA is 21.5%. An increasing number of chemicals used in industrial production, households, and services are associated with the incidence of adult-onset asthma attributable to exposure to chemicals. This review article summarizes the different types of WRA and describes diagnostic procedures, treatment, prevention, and approaches to patient management. It is not always easy to distinguish between OA and WEA. It is important to establish a diagnosis (of sensitizer-/irritant-induced OA or WEA) in order to prevent worsening of symptoms, as well as to prevent other workers from being exposed, by providing early treatment and counseling on social security and work-related issues.

Assessment and Management of Occupational Asthma

Exposures at work can give rise to different phenotypes of "work-related asthma." The focus of this review is on the diagnosis and management of sensitizer-induced occupational asthma (OA) caused by either a high- or low-molecular-weight agent encountered in the workplace. The diagnosis of OA remains a challenge for the clinician because there is no simple test with a sufficiently high level of accuracy. Instead, the diagnostic process combines different procedures in a stepwise manner. These procedures include a detailed clinical history, immunologic testing, measurement of lung function parameters and airway inflammatory markers, as well as various methods that relate changes in these functional and inflammatory indices to workplace exposure. Their diagnostic performances, alone and in combination, are critically reviewed and summarized into evidence-based key messages. A working diagnostic algorithm is proposed that can be adapted to the suspected agent, purpose of diagnosis, and available resources. Current information on the management options of OA is summarized to provide pragmatic guidance to clinicians who have to advise their patients with OA.

Allergic and Respiratory Symptoms in Employees of Indoor Cannabis Grow Facilities

BACKGROUND

While little is known about the occupational hazards associated with Cannabis cultivation, both historical research in the hemp industry and preliminary data from modern grow houses, suggest that Cannabis workers may be at increased risk of respiratory and allergic diseases.

OBJECTIVES

We sought to investigate the association between workplace exposures and health symptoms in an indoor Cannabis grow facility in Washington State, USA.

METHODS

We performed a cross-sectional study with all consenting employees in an indoor Cannabis grow facility in Seattle, WA using a questionnaire. The questionnaire gathered data on respiratory, ocular, nasal, and dermal symptoms. A subset of employees with work-related symptoms underwent repeated cross-shift and cross-week measurement of spirometry, fractional exhaled nitrogen oxide (FeNO), and skin prick testing for Cannabis sensitization. Exposure to Cannabis dust was classified based on self-described tasks, expert opinion, and exposure monitoring of particulate matter. Multivariable logistic regression was undertaken to examine associations between exposure to Cannabis dust (classified as low, medium, and high) and health symptoms. Linear mixed effects models examined the relationship between cross-shift and cross-week changes in spirometry and FeNO.

RESULTS

Ninety-seven percent (97%) of the employees (n = 31) surveyed were recreational cannabis users, with 81% (n = 25) smoking cannabis multiple times per day. Twenty-two (71%) employees reported one or more work-related symptoms: 65% respiratory, 39% ocular, 32% nasal, and 26% dermal symptoms. There was a trend toward increased likelihood of work-related symptoms with increasing exposure to Cannabis dust, although none of these results were statistically significant. Of the 10 employees with work-aggravated symptoms, 5 had borderline-high or high FeNO, 7 had abnormal spirometry, and 5 had evidence of Cannabis sensitization on skin prick testing. FeNO increased by 3.78 ppb (95% confidence interval 0.68-6.88 ppb) across the work-week and there was a trend toward cross-week and cross-shift reduced airflow.

CONCLUSIONS

We found a high prevalence of work-related allergic- and particularly respiratory symptoms in the employees of one indoor Cannabis grow facility in Washington State. A high proportion of employees with work-aggravated symptoms had findings consistent with probable work-related asthma based on high FeNO, airflow obstruction on spirometry, and Cannabis sensitization on skin prick testing. However, due to the high incidence of recreational cannabis use among these workers, the relative influence of occupational versus recreational exposure to Cannabis dust on the respiratory health and sensitization status of these workers could not be resolved in this study.

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.

Sudan red dye: a new agent causing type-2 occupational asthma

Background

Sudan red or 1-[(2-methoxyphenyl)azo]-2-naphthol is a low molecular weight azoic agent widely used in industry, particularly in the production of hair dyes. The use of this product in the food industry is prohibited due to its potential carcinogenic effect, but no respiratory involvement has been reported to date.

Case presentation

We present the case of a 46-year-old female patient who had been working in a cosmetics packaging company for 20 years. The patient developed occupational asthma to a red azo dye known as Sudan red. The diagnosis was confirmed by specific bronchial provocation test. Induced sputum samples were obtained previously and in the 24 h following the procedure, with a rise in the percentage of eosinophils from 10 to 65%.

Conclusions

This report describes the case of a patient who developed OA caused by exposure to an azoic dye called Sudan red. The clinical and analytical features suggest a type 2-related asthma; however, we are not yet able to confirm the specific pathophysiological mechanism. The extensive use of azo dyes in industry means that it is particularly important to describe their implications for health, which are probably underestimated at present.

Bronchial Response to High and Low Molecular Weight Occupational Inhalant Allergens

PURPOSE

Occupational asthma may be induced by high- or low-molecular weight allergens (HMWA or LMWA, respectively). The study was conducted to compare the pattern of bronchial response in 200 HMWA-induced asthmatics (n = 130) and LMWA-induced asthmatics (n = 70).

METHODS

The study participants underwent a single-blind, placebo-controlled specific inhalation challenge (SIC) with workplace allergens, accompanied by evaluation of non-specific bronchial hyperresponsiveness (NSBHR) with methacholine before and after the SIC.

RESULTS

A single early bronchial response more frequently occurred in HMWA-induced asthmatics than in LMWA-induced asthmatics (86.2% vs. 20%). An isolated late bronchial response or atypical patterns were more frequently observed in LMWA-induced asthmatics than in LMWA-induced asthmatics (45.7% vs. 3.8% or 34.3% vs. 10%, respectively). Baseline NSBHR before SIC was more often detected in LMWA-induced asthmatics than in HMWA-induced asthmatics (81.4% vs. 54.6%), and the median value of the provocation concentration of methacholine was relevantly lower in these patients before and after SIC. A significant 3-fold increase in NSBHR after SIC was observed more often in LMWA-induced asthmatics than in HMWA-induced asthmatics (82.8% vs. 66.1%). In addition, compared to LMWA-induced asthmatics, HMWA-induced asthmatics were older, were more frequently active smokers, showed lower level of NSBHR, and more frequently continued their work in harmful occupational exposure.

CONCLUSIONS

The results of this study suggest that HMWA-induced asthmatics may have milder clinical courses and that there is a possibility of job continuation despite asthma exacerbation requiring medical surveillance.

Are high- and low-molecular-weight sensitizing agents associated with different clinical phenotypes of occupational asthma?

BACKGROUND

High-molecular-weight (HMW) proteins and low-molecular-weight (LMW) chemicals can cause occupational asthma (OA) although few studies have thoroughly compared the clinical, physiological, and inflammatory patterns associated with these different types of agents. The aim of this study was to determine whether OA induced by HMW and LMW agents shows distinct phenotypic profiles.

METHODS

Clinical and functional characteristics, and markers of airway inflammation were analyzed in an international, multicenter, retrospective cohort of subjects with OA ascertained by a positive inhalation challenge response to HMW (n = 544) and LMW (n = 635) agents.

RESULTS

Multivariate logistic regression analysis showed significant associations between OA caused by HMW agents and work-related rhinitis (OR [95% CI]: 4.79 [3.28-7.12]), conjunctivitis (2.13 [1.52-2.98]), atopy (1.49 [1.09-2.05]), and early asthmatic reactions (2.86 [1.98-4.16]). By contrast, OA due to LMW agents was associated with chest tightness at work (2.22 [1.59-3.03]), daily sputum (1.69 [1.19-2.38]), and late asthmatic reactions (1.52 [1.09-2.08]). Furthermore, OA caused by HMW agents showed a higher risk of airflow limitation (1.76 [1.07-2.91]), whereas OA due to LMW agents exhibited a higher risk of severe exacerbations (1.32 [1.01-1.69]). There were no differences between the two types of agents in the baseline sputum inflammatory profiles, but OA caused by HMW agents showed higher baseline blood eosinophilia and a greater postchallenge increase in fractional nitric oxide.

CONCLUSION

This large cohort study describes distinct phenotypic profiles in OA caused by HMW and LMW agents. There is a need to further explore differences in underlying pathophysiological pathways and outcome after environmental interventions.

Heterogeneity and the origins of asthma

OBJECTIVE

To examine the roots of asthma across different ages, including atopy, the role of the microbiome and viral infections, and comorbidities and confounders, such as obesity, aspirin-exacerbated respiratory disease, neutrophilic asthma, cigarette smoking, and the possibility of an asthma-chronic obstructive pulmonary disease overlap syndrome.

DATA SOURCES

Data were taken from various scientific search engines, including PubMed and Science Direct databases.

STUDY SELECTIONS

Articles that reviewed information on the origins of asthma in persons of all ages, including different phenotypes and genotypes of asthma, were used.

RESULTS

Asthma is a common and complex disease whose origins are likely a combination of both genetic predisposition and environmental exposures. Factors such as the microbiome, other atopic disease, viral infections in young children, and other diagnoses, such as obesity or aspirin-exacerbated respiratory disease, are important to consider when creating a treatment plan for patients.

CONCLUSION

Asthma is a disease that is often diagnosed in childhood but can present at any age. There is debate in the field as to whether asthma is one disease or several different diseases that include airway inflammation as a key finding. There are risk factors for disease in the environment and through comorbidities that likely play significant roles in the origins of asthma, the development of symptoms, and the response to treatment. These factors are even more important as we look toward the future with the goal of personalized medicine.

Nasal protein profiles in work-related asthma caused by different exposures

BACKGROUND

The mechanisms of work-related asthma (WRA) are incompletely delineated. Nasal cell samples may be informative about processes in the lower airways. Our aim was to determine the nasal protein expression profiles of WRA caused by different kind of exposures.

METHODS

We collected nasal brush samples from 82 nonsmoking participants, including healthy controls and WRA patients exposed to (i) protein allergens, (ii) isocyanates and (iii) welding fumes the day after relevant exposure. The proteome changes in samples were analysed by two-dimensional difference gel electrophoresis, and the differentially regulated proteins found were identified by mass spectrometry. Immunological comparison was carried out using Western blot.

RESULTS

We detected an average of 2500 spots per protein gel. Altogether, 228 protein spots were chosen for identification, yielding 77 different proteins. Compared to the controls, exposure to protein allergens had the largest effects on the proteome. Hierarchical clustering revealed that protein allergen- and isocyanate-related asthma had similar profiles, whereas asthma related to welding fumes differed. The highly overrepresented functional categories in the asthma groups were defence response, protease inhibitor activity, inflammatory and calcium signalling, complement activation and cellular response to oxidative stress. Immunological analysis confirmed the found abundance differences in galectin 10 and protein S100-A9 between the groups.

CONCLUSIONS

Work-related asthma patients exposed to protein allergens and isocyanates elicit similar nasal proteome responses and the profiles of welders and healthy controls were alike. Revealed biological activities of the protein expression changes are associated with allergic inflammation and asthma.

Occupational lung diseases: from old and novel exposures to effective preventive strategies

Occupational exposure is an important, global cause of respiratory disease. Unlike many other non-communicable lung diseases, the proximal causes of many occupational lung diseases are well understood and they should be amenable to control with use of established and effective approaches. Therefore, the risks arising from exposure to silica and asbestos are well known, as are the means of their prevention. Although the incidence of occupational lung disease has decreased in many countries, in parts of the world undergoing rapid economic transition and population growth-often with large informal and unregulated workforces-occupational exposures continue to impose a heavy burden of disease. The incidence of interstitial and malignant lung diseases remains unacceptably high because control measures are not implemented or exposures arise in novel ways. With the advent of innovative technologies, new threats are continually introduced to the workplace (eg, indium compounds and vicinal diketones). In developed countries, work-related asthma is the commonest occupational lung disease of short latency. Although generic control measures to reduce the risk of developing or exacerbating asthma are well recognised, there is still uncertainty, for example, with regards to the management of workers who develop asthma but remain in the same job. In this Review, we provide recommendations for research, surveillance, and other action for reducing the burden of occupational lung diseases.

The Role and Immunobiology of Eosinophils in the Respiratory System: a Comprehensive Review

The eosinophil is a fully delineated granulocyte that disseminates throughout the bloodstream to end-organs after complete maturation in the bone marrow. While the presence of eosinophils is not uncommon even in healthy individuals, these granulocytes play a central role in inflammation and allergic processes. Normally appearing in smaller numbers, higher levels of eosinophils in the peripheral blood or certain tissues typically signal a pathologic process. Eosinophils confer a beneficial effect on the host by enhancing immunity against molds and viruses. However, tissue-specific elevation of eosinophils, particularly in the respiratory system, can cause a variety of short-term symptoms and may lead to long-term sequelae. Eosinophils often play a role in more commonly encountered disease processes, such as asthma and allergic responses in the upper respiratory tract. They are also integral in the pathology of less common diseases including eosinophilic pneumonia, allergic bronchopulmonary aspergillosis, hypersensitivity pneumonitis, and drug reaction with eosinophilia and systemic symptoms. They can be seen in neoplastic disorders or occupational exposures as well. The involvement of eosinophils in pulmonary disease processes can affect the method of diagnosis and the selection of treatment modalities. By analyzing the complex interaction between the eosinophil and its environment, which includes signaling molecules and tissues, different therapies have been discovered and created in order to target disease processes at a cellular level. Innovative treatments such as mepolizumab and benralizumab will be discussed. The purpose of this article is to further explore the topic of eosinophilic presence, activity, and pathology in the respiratory tract, as well as discuss current and future treatment options through a detailed literature review.

New causes of immunologic occupational asthma, 2012-2014

PURPOSE OF REVIEW

The objective of this study was to review all new causes of well documented immunologic occupational asthma (IOA) published in the English and French medical literature between January 2012 and mid-2014.

RECENT FINDINGS

Ten case reports of new causes of IOA were reported during that period. The diagnosis was either confirmed by specific inhalation challenges (n = 5) or a combination of peak expiratory flow monitoring at and off work, confirmation of specific sensitisation, and asthma (n = 3). These involved both high (mites contaminating cured ham, various enzymes used as detergents and food additives, aquarium fish food, and orange allergens) and low-molecular-weight agents (spruce wood dust, a biocide, and an halogenated platinum compound used in cytotoxic drugs). Furthermore, eight studies reported cases of IOA with agents already known as airway sensitizers but in working environments that were unusual and reported for the first time.

SUMMARY

There are more than 400 known causes of IOA and the list grows continuously with the development of new technologies and better recognition of the diagnosis by physicians. IgE-mediated sensitization was confirmed in all new cases involving high-molecular-weight agents and in two of the three new cases involving low-molecular-weight agents. Symptoms of rhinitis were often associated with both types of agents. Physicians should stay alert and suspect occupational asthma in any adult with new-onset asthma or with newly uncontrolled asthma.

Diisocyanate and non-diisocyanate sensitizer-induced occupational asthma frequency during 2003 to 2007 in Ontario, Canada

OBJECTIVE

To investigate proportions and outcomes of isocyanate and other causes of occupational asthma (OA) claims in Ontario, Canada, 2003 to 2007.

METHODS

New accepted workers' compensation claims for OA compensated by the Ontario Workplace Safety and Insurance Board were retrospectively reviewed.

RESULTS

There were 112 allowed claims for OA-30 (26.8%) from diisocyanates (ISO) and 82 (73.2%) from other causes (non-diisocyanates [N-ISO]). The most common occupations for ISO OA were production workers (50%). The most common agents in the N-ISO group were flour (13%) and metal dusts/fumes (10%). At a median time of 8 months postdiagnosis, 55% of ISO and 56.4% of N-ISO workers, respectively, were unemployed.

CONCLUSIONS

Diisocyanates OA compensation claims in Ontario are recognized at a lower absolute number and proportion of all OA claims than those in earlier periods. More than half from all causes were unemployed at a median of 8 months postdiagnosis.

Asthma risk factors

BACKGROUND

Bronchial asthma is one of the most common chronic diseases in childhood, with a current prevalence of 6% to 9%, but a prevalence that is increasing at an alarming rate. Asthma is a complex genetic disorder with strong environmental influence. It imposes a growing burden on our society in terms of morbidity, quality of life, and healthcare costs. Despite large-scale efforts, only a few asthma genes have been confirmed, suggesting that the genetic underpinning of asthma is highly complex.

METHODS

A review of the literature was performed regarding atopic and nonatopic asthma risk factors, including environmental risk factors and genetic studies in adults and children.

RESULTS

Several environmental risk factors have been identified to increase the risk of developing asthma such as exposure to air pollution and tobaccos smoke as well as occupational risk factors. In addition atopy, stress, and obesity all can increases the risk for asthma in genetically susceptible persons.

CONCLUSION

Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma in all age groups indicate that our living environment and immunity are in imbalance with each other reacting with airway inflammation to the environmental exposures and often non-harmful proteins, such as allergens causing the current "asthma and allergy epidemic." Because of the close relationship between asthma and chronic rhinosinusitis, it is important that otolaryngologists have a good understanding of asthma, the etiologic factors associated with disease, and its evaluation and management.

Prevalence of Work-Related Asthma and its Impact in Primary Health Care

BACKGROUND AND OBJECTIVE

To determine the prevalence of occupational asthma (OA) and work-exacerbated asthma (WEA) among asthmatic patients diagnosed in Primary Health Care (PHC). To analyze the impact at PHC level caused by under-diagnosis and inappropriate referral of OA.

PATIENTS AND METHODS

A descriptive, cross-sectional multicenter study in patients aged between 16 and 64years diagnosed with asthma, according to their medical record; all were working or had worked, and were assigned to one of 16 PHC centers in a healthcare district. Based on the responses to the questionnaire completed at the study visit, which included a thorough review of the subject's entire working history, patients were classified into three categories by an expert in occupational asthma: OA, WEA or common asthma (CA).

RESULTS

Three hundred and sixty-eight patients completed the questionnaire. The prevalence of OA was 18.2% (25% in men and 14.6% in women, P=.046), and 54 patients (14.7%) were classified as WEA. The proportion of patients with work-related asthma (WRA) was therefore 32.9%. Asthmatic patients with WRA took more sick leave than CA patients (P<.001).

CONCLUSIONS

A high prevalence of WRA was found, mostly treated in PHC. Under-diagnosis of WRA is widespread in PHC.

EAACI position paper: irritant-induced asthma

The term irritant-induced (occupational) asthma (IIA) has been used to denote various clinical forms of asthma related to irritant exposure at work. The causal relationship between irritant exposure(s) and the development of asthma can be substantiated by the temporal association between the onset of asthma symptoms and a single or multiple high-level exposure(s) to irritants, whereas this relationship can only be inferred from epidemiological data for workers chronically exposed to moderate levels of irritants. Accordingly, the following clinical phenotypes should be distinguished within the wide spectrum of irritant-related asthma: (i) definite IIA, that is acute-onset IIA characterized by the rapid onset of asthma within a few hours after a single exposure to very high levels of irritant substances; (ii) probable IIA, that is asthma that develops in workers with multiple symptomatic high-level exposures to irritants; and (iii) possible IIA, that is asthma occurring with a delayed-onset after chronic exposure to moderate levels of irritants. This document prepared by a panel of experts summarizes our current knowledge on the diagnostic approach, epidemiology, pathophysiology, and management of the various phenotypes of IIA.

Work aggravated asthma; a review of the recent evidence

BACKGROUND

The link between asthma and inhaled workplace exposures has been long appreciated, and yet aggravation of asthma symptoms by work conditions, known as work-aggravated asthma (WAA), remains relatively common.

SOURCES OF DATA

A review of the literature published over the last 3 years was carried out, and additional key articles were included from outside this timeframe.

AGREEMENT

WAA is commonly reported by workers with asthma. One published assessment of 12 studies identified a median prevalence of 21.5% among workers with asthma. Commonly reported causes included a variety of inhaled dusts, smoke, vapours, fumes, gases and mists, common and workplace-specific aeroallergens, physical environmental factors including temperature and humidity and physical activity at work.

CONTROVERSY

Remains in relation to definition, and how to distinguish WAA from occupational asthma in which there is sensitization to an agent in the workplace. Both these areas, and the development of workplace interventions to reduce WAA, are timely topics for future research.

Occupational asthma: an overview

Occupational asthma is a form of asthma that is often under-diagnosed and under-reported. Unrecognized occupational asthma can lead to progression of disease and increased morbidity. The medical history is a critical element for establishing a diagnosis of OA. The history should include a detailed assessment of the workplace environment, the work process, changes in symptoms in and away from the workplace, and a review of relevant material safety data sheets that may provide clues regarding exposure(s) and the potential cause(s). Objective testing including spirometry pre- and post-bronchodilators, peak expiratory flow rate monitoring in and out of the workplace, provocation testing (i.e., methacholine challenge) to assess for airway hyperresponsiveness, and, if feasible, specific provocation by experienced personnel in a controlled setting to a suspected inciting agent are necessary for confirming a diagnosis. Skin or serologic testing for specific IgE to aeroallergens to assess the worker's atopic status is useful especially when considering certain forms of OA where atopy is a risk factor. Specialized laboratory testing may be useful for specific OA causes. It is important to correctly make the diagnosis of OA as the impact on the worker's future employment and earning power can be significantly affected.

Occupational asthma

Occupational asthma has been defined as asthma due to conditions attributable to work exposures, not to causes outside the workplace. This review focuses on current data on pathogenesis, evaluation, and management.

The role of chelation in the treatment of other metal poisonings

These proceedings will review the role of chelation in five metals-aluminum, cadmium, chromium, cobalt, and uranium-in order to illustrate various chelation concepts. The process of "chelation" can often be oversimplified, leading to incorrect assumptions and risking patient harm. For chelation to be effective, two critical assumptions must be fulfilled: the presumed "metal toxicity" must correlate with a given body or a particular compartment burden, and reducing this compartmental or the body burden (through chelation) attenuates toxicity. Fulfilling these assumptions requires an established dose-response relationship, a validated, reproducible means of toxicity assessment (clinical, biochemical, or radiographical), and an appropriate assessment mechanisms of body or compartment burden. While a metal might "technically" be capable of chelation (and readily demonstrable in urine or feces), this is an insufficient endpoint. Clinical relevance must be affirmed. Deferoxamine is an accepted chelator for appropriately documented aluminum toxicity. There is a very minimal treatment window in order to address chelation in cadmium toxicity. In acute toxicity, while no definitive chelation benefit is described, succimer (DMSA), diethylenetriaminepentaacetate (DTPA), and potentially ethylenediaminetetraacetic acid (EDTA) have been considered. In chronic toxicity, chelation is unsupported. There is little evidence to suggest that currently available chromium chelators are efficacious. Similarly, scant human evidence exists with which to provide recommendation for cobalt chelation. DTPA has been recommended for cobalt radionuclide chelation, although DMSA, EDTA, and N-acetylcysteine have also been suggested. DTPA is unsupported for uranium chelation. Sodium bicarbonate is currently recommended, although animal evidence is conflicting.

Other asthma considerations

Asthma is a heterogeneous syndrome of cough, wheeze, dyspnea, and chest tightness. However, in a subset of patients, these symptoms may indicate a different underlying disease process with variable responsiveness to classic asthma therapies. Disease may progress while practitioners attempt conventional asthma therapy. Additionally, some types of asthma may require alternative approaches to relieve symptoms successfully. This article describes the differential diagnosis of asthma and discusses some of the more common asthma variants and asthma mimickers.

New occupational and environmental causes of asthma and extrinsic allergic alveolitis

Asthma and extrinsic allergic alveolitis (EAA) remain prevalent respiratory diseases and the cause of a significant disease burden. This article reviews the recent occupational and environmental causes described for these conditions. Even over the limited time spam addressed by this article, novel agents and new data relating to already suggested causes have been described. Various types of work tasks or exposures are described that appear to cause both asthma and EAA. Isocyanates, the best example of dual potential to cause asthma and EAA are discussed, as is the new understanding of the role metal-working fluids play when causing respiratory diseases.

Occupational asthma incidence: findings from the behavioral risk factor surveillance system asthma call-back survey--United States, 2006-2009

BACKGROUND

Occupational asthma (OA) is new-onset asthma or the recurrence of previously quiescent asthma caused by workplace exposures.

OBJECTIVE

To estimate the incidence of population-based new-onset OA and the proportion of incident asthma that is work-related.

METHODS

Behavioral Risk Factor Surveillance System and Asthma Call-back Survey data collected from persons aged ≥18 years during 2006-2009 in 38 states and the District of Columbia were analyzed. Incident health professional-diagnosed new-onset OA cases were persons whose asthma was diagnosed for the first time within the past 12 months whose health professional indicated their asthma was related to their work. Incident potential new-onset OA cases were persons with asthma diagnosed within the past 12 months who did not have health professional-diagnosed work-related asthma but described their asthma as caused by workplace exposures. The proportion of incident asthma that is work-related was calculated using the 2006-2008 estimate of adult asthma incidence (3800 per million).

RESULTS

The estimated annual incidence of health professional-diagnosed new-onset OA was 179 (95% CI: 113-245) per million population. For combined health professional-diagnosed and potential new-onset OA the incidence was 692 (95% CI: 532-853) per million population. The proportion of incident asthma among adults that is work-related was 4.7% for health professional-diagnosed new-onset OA and 18.2% for combined health professional-diagnosed and potential new-onset OA.

CONCLUSIONS

New-onset asthma in as many as one of six adult patients might be associated with work. Clinicians should consider the role of occupational exposures when evaluating adults with incident asthma which may uncover opportunities for early intervention and reversal of an otherwise chronic disease.

RADS and its variants: asthma by another name

This article describes the different clinical variants of irritant-induced asthma, specifically focusing on high-dose irritant-induced asthma and irritant-induced work-exacerbated asthma, as well as reviews known causes, addresses the often adverse medical and socioeconomic outcomes of this complex condition, and considers issues of causation from an occupational and environmental medicine perspective.

The current diagnostic role of the specific occupational laboratory challenge test

PURPOSE OF REVIEW

Classically, the specific occupational challenge test has been considered as the reference test in the diagnosis of occupational asthma. The present study assesses the usefulness of this test for diagnosing this disease and compares it with other diagnostic methods.

RECENT FINDINGS

Occupational asthma is the most frequent work-related respiratory disease in developed countries. Its correct diagnosis is vitally important not only from the medical point of view, but also in view of the disease's major socio-economic repercussions both for the patient and for society as a whole. Diagnosis is based on clinical suspicion of bronchial asthma and of a possible association with the patient's occupation. Various diagnostic strategies have been proposed, including clinical history, immunological test, spirometry, the study of peak flow, the methacholine test and the specific occupational challenge test, as well as studies of bronchial inflammation using noninvasive methods.

SUMMARY

The specific occupational challenge test remains the reference test for the diagnosis of occupational asthma for causal agents of both high and low molecular weight.

Diagnostic utility of exhaled breath condensate analysis in conjunction with specific inhalation challenge in individuals with suspected work-related asthma

BACKGROUND

Establishing the role of exhaled breath condensate (EBC) analysis in work-related asthma (WRA), and more specifically, in conjunction with specific inhalation challenge (SIC), is difficult.

OBJECTIVE

To measure EBC pH, and nitrite/nitrate concentrations before and after SIC in individuals with suspected WRA exposed to either high-molecular-weight (HMW) or low-molecular-weight (LMW) agents and evaluate whether these changes are useful to distinguish between occupational asthma (OA) and work-exacerbated asthma (WEA).

METHODS

One hundred twenty-five consecutive workers undergoing SIC were enrolled. Exhaled breath condensate was collected at the end of the baseline day and 24 hours after exposure to the offending agent. In all EBC samples, pH was measured, and nitrite and nitrate concentrations were determined.

RESULTS

Specific inhalation challenge was positive in 66 individuals, who were then diagnosed with OA. Work-exacerbated asthma was diagnosed in 14, and in 45 patients establishing a direct relationship between the symptoms and work exposure was not possible. In patients with WEA, EBC pH values after SIC were significantly lower than those before SIC (P = .0047). Using the receiver operating characteristic (ROC) curve, we found that an EBC pH decrease of greater than 0.4 units after SIC achieved the most satisfactory sensitivity 79% (confidence interval [CI]: 49-94) and specificity of 100% (CI: 68-100), considering only patients with asthma and without OA. A decrease in EBC pH of 0.4 or more common in those exposed to HMW agents (8/19, 42%) than in those exposed to LMW agents (7/47, 15%).

CONCLUSIONS

Exhaled breath condensate pH in conjunction with SIC may be useful for diagnosing WEA.