Frequency of work-related respiratory symptoms in workers without asthma

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.

Diagnosing occupational asthma

Making an accurate diagnosis of occupational asthma (OA) is, generally, important. The condition has not only significant health consequences for affected workers, but also substantial socio-economic impacts for workers, their employers and wider society. Missing a diagnosis of OA may lead to continued exposure to a causative agent and progressive worsening of disease; conversely, diagnosing OA when it is not present may lead to inappropriate removal from exposure and unnecessary financial and social consequences. While the most accurate investigation is specific inhalation challenge in an experienced centre, this is a scarce resource, and in many cases, reliance is on other tests. This review provides a technical dossier of the diagnostic value of the available methods which include an appropriate clinical history, the use of specific immunology and measurement of inflammatory markers, and various methods of relating functional changes in airway calibre to periods at work. It is recommended that these approaches are used iteratively and in judicious combination, in cognizance of the individual patient's circumstances and requirements. Based on available evidence, a working diagnostic algorithm is proposed that can be adapted to the suspected agent, purpose of diagnosis and available resources. For better or worse, many of the techniques - and their interpretation - are available only in specialized centres and where there is room for doubt, referral to such a centre is probably wise. Accordingly, the implementation or development of such specialized centres with appropriate equipment and expertise should greatly improve the diagnostic evaluation of work-related asthma.

Does the medical diagnosis of occupational asthma coincide with the legal diagnosis?

OBJECTIVE

The incidence of occupational asthma (OA) is increasing worldwide. In this study, we first aimed to document the rate of diagnosis of OA among patients who were referred to our clinic from the Social Security Institution and the factors that affected diagnosis; secondly, we aimed to assess the consistency of the medical and legal diagnoses.

METHODS

The study involved 132 consecutive patients who were referred to our clinic for the evaluation of OA between 2010 and 2015. Detailed workplace history, the tools used in the diagnosis such as peak expiratory flow (PEF) monitoring and bronchial provocation tests, and the final medical diagnosis were recorded from case files.

RESULTS

Asthma was diagnosed in 75% (n = 99) of the patients. Among them, 22.2% were diagnosed as having OA. The diagnosis was confirmed by serial PEF measurements, non-specific bronchial hyperreactivity assessment or both of the tests both at work and off-work periods. OA diagnosis was mostly established in active workers (72.7%). The legal diagnosis period was completed in 54.5% of these 22 patients, and 50% (n = 11) were officially diagnosed as having OA with a 91.6% concordance with medical diagnosis.

CONCLUSION

This study verifies the importance of diagnosing asthma correctly as a first step in the evaluation of OA. Diagnostic tests other than specific provocation tests could be preferential in patients who still work in the same field. We believe that cooperation with the patient's occupational physician and adequate recognition of the work environment will improve the consistency of legal and medical diagnoses.

EAACI Position Paper on assessment of cough in the workplace

Cough is a nonspecific and relatively common symptom that can present difficulties in diagnosis and management, particularly when it is reported to be associated with the workplace. The present consensus document, prepared by a taskforce of the Interest Group on Occupational Allergy of the European Academy of Allergy and Clinical Immunology by means of a nonsystematic review of the current literature, is intended to provide a definition and classification of work-related chronic cough (WRCC) to assist the daily practice of physicians facing with this symptom. The review demonstrates that several upper and lower airway work-related diseases may present with chronic cough; hence, the possible link with the workplace should always be considered. Due to the broad spectrum of underlying diseases, a multidisciplinary approach is necessary to achieve a definite diagnosis. Nevertheless, more epidemiological studies are necessary to estimate the real prevalence and risk factors for WRCC, the role of exposure to environmental and occupational sensitizers and irritants in its pathogenesis and the interaction with both upper and lower airways. Finally, the best management option should be evaluated in order to achieve the best outcome without adverse social and financial consequences for the worker.

A comparison of work-exacerbated asthma cases from clinical and epidemiological settings

BACKGROUND

Clinical and epidemiological studies commonly use different case definitions in different settings when investigating work-exacerbated asthma (WEA). These differences are likely to impact characteristics of the resulting WEA cases.

OBJECTIVES

To investigate this issue by comparing two groups of WEA cases, one identified using an intensive clinical evaluation and another that fulfilled epidemiological criteria.

METHODS

A total of 53 clinical WEA cases had been referred for suspected work-related asthma to two tertiary clinics in Canada, where patients completed tests that confirmed asthma and ruled out asthma caused by work. Forty-seven epidemiological WEA cases were employed asthma patients treated at a health maintenance organization in the United States who completed a questionnaire and spirometry, and fulfilled criteria for WEA based on self-reported, work-related worsening of asthma and relevant workplace exposures as judged by an expert panel.

RESULTS

Using different case criteria in different settings resulted in case groups that had a mix of similarities and differences. The clinical WEA cases were more likely to have visited a doctor's office ≥3 times for asthma in the past year (75% versus 11%; P<0.0001), but did not seek more asthma-related emergency or in-patient care, or have lower spirometry values. The two groups differed substantially according to the industries and occupations where the cases worked.

CONCLUSIONS

Findings from both types of studies should be considered when measuring the contribution of work to asthma exacerbations, identifying putative agents, and selecting industries and occupations in which to implement screening and surveillance programs.

Asthma related to cleaning agents: a clinical insight

OBJECTIVE

To determine the agents causing asthmatic reactions during specific inhalation challenges (SICs) in workers with cleaning-related asthma symptoms and to assess the pattern of bronchial responses in order to identify the mechanisms involved in cleaning-related asthma.

DESIGN

A retrospective case series analysis.

SETTING

The study included all participants who completed an SIC procedure with the cleaning/disinfection products suspected of causing work-related asthma over the period 1992-2011 in a tertiary centre, which is the single specialised centre of the French-speaking part of Belgium where all participants with work-related asthma are referred to for SIC.

RESULTS

The review identified 44 participants who completed an SIC with cleaning/disinfection agents. Challenge exposure to the suspected cleaning agents elicited a ≥20% fall in forced expiratory volume in 1 s (FEV1) in 17 (39%) participants. The cleaning products that induced a positive SIC contained quaternary ammonium compounds (n=10), glutaraldehyde (n=3), both of these agents (n=1) and ethanolamines (n=2). Positive SICs were associated with a significant decrease in the median (IQR) value of the provocative concentration of histamine causing a 20% fall in FEV1 (PC20) from 1.4 (0.2-4.2) mg/mL at baseline to 0.5 (0.4-3.0) mg/mL after the challenge and a significant increase in sputum eosinophils from 1.8 (0.8-7.2)% at baseline to 10.0 (4.1-15.9)% 7 h after the challenge exposure while these parameters did not significantly change in participants with a negative SIC. Overall, 11 of 17 participants with positive SICs showed greater than threefold decrease in postchallenge histamine PC20 value, a >2% increase in sputum eosinophils, or both of these outcomes.

CONCLUSIONS

These data indicate that a substantial proportion of workers who experience asthma symptoms related to cleaning materials show a pattern of bronchial reaction consistent with sensitiser-induced occupational asthma. The results also suggest that quaternary ammonium compounds are the principal cause of sensitiser-induced occupational asthma among cleaners.

Respiratory symptoms and respiratory-related absence from work among health care workers in Sweden

OBJECTIVE

To investigate respiratory symptoms and respiratory-related absence from work among Swedish health care workers (HCWs).

METHODS

From a postal questionnaire study among a general Swedish working population (n = 12,186), we identified 2156 HCW (555 assistant nurses, 377 nurses, 109 physicians, and 1115 others), including 429 with mainly cleaning tasks (HCW-cleaning). The remaining respondents were classified as non-HCW. Multiple logistic regressions with 95% confidence intervals (CIs) were used to compare respiratory symptoms and respiratory-related absence from work between HCW and non-HCW, adjusting for potential confounders.

RESULTS

The prevalence of adult onset asthma was 4.3% in HCW and 3.0% in non-HCW (p = .003). Asthmatic symptoms during the past year were reported mainly by HCW-cleaning, 14.7%, in comparison to 8.3% among non-HCW (p < .0001). HCW had an increased odds ratio (OR) for asthmatic symptoms during the past year (OR 1.3, 95% CI (1.1-1.5)) and more prominent among assistant nurses (OR 1.5, 95% CI (1.1-2.0)) and HCW-cleaning (OR 1.9, 95% CI (1.4-2.5)). Respiratory-related absence from work in the past year was reported by 1.4% of non-HCW, 3.0% of HCW-cleaning, 2.9% of nurses, and 1.6% of assistant nurses. Taking smoking and age into account, there was still significantly increased respiratory-related absence from work in nurses (OR 2.0, 95% CI (1.1-3.8)) and in HCW-cleaning (OR 2.1, 95% CI (1.2-3.7)).

CONCLUSIONS

HCW in Sweden, especially those with cleaning tasks, reported more respiratory symptoms and respiratory-related absence from work than the general working population. There is a need for longitudinal studies with detailed information on both occupational exposures and socioeconomic factors to explore what influences respiratory-related absence from work among HCW.

Work-exacerbated asthma and occupational asthma: do they really differ?

BACKGROUND

Although work-exacerbated asthma (WEA) is a prevalent condition likely to have an important societal burden, there are limited data on this condition.

OBJECTIVES

The aims of this study were (1) to compare the clinical, functional, and inflammatory characteristics of workers with WEA and occupational asthma (OA) and (2) compare health care use and related costs between workers with WEA and OA, as well as between workers with work-related asthma (WRA; ie, WEA plus OA) and those with non-work-related asthma (NWRA) in a prospective study.

METHODS

We performed a prospective observational study of workers with and without WRA with a 2-year follow-up. The diagnosis of OA and WEA was based on the positivity and negativity of results on specific inhalation challenges, respectively.

RESULTS

One hundred fifty-four subjects were enrolled: 53 with WEA, 68 with OA, and 33 control asthmatic subjects (NWRA). WEA was associated with more frequent prescriptions of inhaled corticosteroids (odds ratio [OR], 4.4; 95% CI, 1.4-13.6; P = .009), a noneosinophilic phenotype (OR, 0.3; 95% CI, 0.1-0.9; P = .04), a trend toward a lower FEV1 (OR, 0.9; 95% CI, 0.9-1.0; P = .06), and a higher proportion of smokers (OR, 2.5; 95% CI, 0.96-9.7; P = .06) than the diagnosis of OA. The health care use of WRA and related costs were 10-fold higher than those of NWRA.

CONCLUSION

Workers with WEA appeared to have features of greater asthma severity than workers with OA. In contrast with OA, WEA was associated with a noneosinophilic phenotype. Both OA and WEA were associated with greater health care use and 10-fold higher direct costs than NWRA.

Upper airway symptoms among workers with work-related respiratory complaints

BACKGROUND

Work-related rhinitis and asthma symptoms frequently co-exist.

AIMS

To determine the prevalence and nature of nasal, pharyngeal, laryngeal and sinus symptoms among individuals with work-related respiratory symptoms.

METHODS

Individuals referred to a tertiary occupational asthma clinic for investigations with specific inhalation challenges were evaluated using the RHINASTHMA quality of life questionnaire and a questionnaire that assessed the nature and frequency of upper airway symptoms, their relationship to the workplace and their temporal relationship with the onset of asthma symptoms.

RESULTS

There were 83 study participants. At least one upper airway symptom was reported by all of these individuals: nasal in 92%; pharyngeal in 82%; laryngeal in 65% and sinus in 53% of participants. Overall, there were no significant differences in the frequencies of nasal, pharyngeal, laryngeal and sinus symptoms when comparing these with occupational asthma (OA), work-exacerbated asthma (WEA) and work-related respiratory symptoms (WRS), except that nasal bleeding was most frequent among those with WRS. The presence of laryngeal symptoms was significantly associated with rhinitis-specific quality of life impairment. Individuals with workplace exposures to high molecular weight agents had greater impaired quality of life than those who were exposed to low molecular weight agents (RHINASTMA Upper Airway sub-scores: 24.0±10.4 versus 19.8±6.8; P < 0.05).

CONCLUSIONS

Individuals who were referred for work-related respiratory symptoms experienced high rates of work-related nasal, pharyngeal, laryngeal and sinus symptoms, regardless of having OA, WEA or WRS.

Clinical assessment of occupational asthma and its differential diagnosis

Occupational asthma (OA) is defined as asthma caused by sources and conditions attributable to a particular occupational environment and not to stimuli encountered outside the workplace. Two types of OA are distinguished based on their appearance after a latency period or not. The most frequent type appears after a latency period leading to sensitization; the clinical assessment of this type of OA is the topic of this review. The differential diagnosis of OA is also reviewed, including work-exacerbated asthma, eosinophilic bronchitis, hyperventilation syndrome, vocal cord dysfunction, bronchiolitis, and other causes of dyspnea or cough.

Prolonged exposure to damp and moldy workplaces and new-onset asthma

PURPOSE

Epidemiological evidence shows that indoor dampness is associated with respiratory symptoms, the aggravation of preexisting asthma, and the development of new-onset asthma. Follow-up studies indicate that symptoms compatible with asthma constitute risk factors for the future development of asthma. The aims of the study were (1) to assess whether asthma-like symptoms (cough, dyspnea, and wheeze) that occur in relation to exposure to damp and moldy work environments lead to the later development of asthma and (2) to assess the importance of continued exposure to indoor dampness and molds at work in the development of asthma.

METHODS

We followed 483 patients with asthma-like symptoms related to damp workplaces but without objective evidence of asthma in baseline examinations. The development of asthma and present work conditions were established with the use of a questionnaire 3-12 years later.

RESULTS

A total of 62 patients (13%) reported having developed asthma during the study period. Continued exposure to a damp or moldy environment was associated with a more than fourfold increase in the risk of asthma (odds ratio 4.6, 95% confidence interval 1.8-11.6). Working in a non-remediated environment at follow-up was the strongest risk factor for developing asthma. The remediation of damp buildings seemed to be associated with a decrease in the risk of asthma.

CONCLUSIONS

The results indicate that exposure at work to dampness and molds is associated with the occurrence of new-onset asthma. Exposed workers suffering from asthma-like symptoms represent a risk group for the development of asthma. The risk appears especially high if the exposure continues. Due to inherent weaknesses of patient series, the findings need corroborative studies.

Asthma and rhinitis in the workplace

Accumulating evidence indicates that the workplace environment substantially contributes to the global burden of asthma and rhinitis. Work-related asthma and rhinitis represent a public health concern due to their health and socioeconomic impacts. This article summarizes the scientific evidence on sensitizer-induced occupational asthma and rhinitis that has been published during the past 5 years. The review addresses the strategies for diagnosing and managing these highly prevalent occupational diseases.

Occupational exposures as risk factors for asthma and allergic diseases in a Turkish population

PURPOSE

There has been no community-based epidemiological study on the relation of occupational exposures with asthma, rhinitis, and eczema in Turkey. We examined the relationship between occupational exposures and adult-onset asthma, wheezing, allergic rhinitis, and eczema in a Turkish adult population.

METHODS

The data was collected from 1,047 adults, selected randomly from five distant family health centers. Questionnaires were filled by family practitioners with the help of interviews. The data included physician-diagnosed asthma, allergic rhinitis, eczema, wheezing, and occupational exposures.

RESULTS

Wheezing in all the subjects was associated with past exposure to irritants (OR: 1.7, 95%CI: 1.0-2.9), wood/coal smoke (OR: 2.3, 95%CI: 1.0-5.3), metal dust (OR: 2.6, 95%CI: 1.2-5.7), volatile fumes (OR: 2.5, 95%CI: 1.1-5.3), and paper dust (OR: 3.7, 95%CI: 1.5-8.9). Past exposure to dust (OR: 4.1, 95%CI: 1.2-14.2) and to irritants (OR: 6.5, 95%CI: 2.0-20.4) were associated with increased prevalence of wheezing in nonsmokers, whereas current exposure to irritants was associated with decreased prevalence of wheezing (OR: 0.1, 95%CI: 0.01-0.9) in these subjects. In subjects who were regular smokers, exposure to metal dust (OR: 2.8, 95%CI: 1.2-6.5), volatile fumes (OR: 2.3, 95%CI: 1.0-5.3), and paper dust (OR: 3.3, 95%CI: 1.3-8.6) were the main causes for wheezing. Physician-diagnosed eczema was associated with occupational exposure to chemical fumes (OR: 3.7, 95%CI: 1.3-10.6).

CONCLUSION

The present study showed that occupational exposures were associated with wheezing and eczema prevalence in the studied population. Nonsmokers could be more vulnerable to respiratory effects of occupational exposures due to healthy smokers effect.