Outcome of Occupational Asthma in Patients With Continuous Exposure: A 3-Year Longitudinal Study During Pharmacologic Treatment

doi:10.1378/chest.124.6.2372

Chest

Volume 124, Issue 6, December 2003, Pages 2372-2376

https://doi.org/10.1378/chest.124.6.2372 Get rights and content

Study objective

To evaluate the effect of treatment with beclomethasone dipropionate (500 μg bid) and salmeterol (50 μg bid) on lung function and respiratory symptoms in 20 subjects with occupational asthma (OA) still exposed to the work environment cause of their disease.

Methods

At enrollment and every 6 months for 3 years, respiratory symptom score (from 0 [no symptoms] to 2 [moderate-to-severe symptoms]), spirometry, methacholine challenge, peak expiratory flow (PEF) variability, and the use of rescue salbutamol were evaluated. During the 3 years of follow-up, 10 subjects were excluded from the study because they retired or changed jobs.

Measurements and results

Symptoms of work-related asthma started 12.6 ± 13.1 years (mean ± SD) before diagnosis. At baseline, mean FEV₁ was 80.2% of predicted values and provocative dose of methacholine causing a 20% fall in FEV₁ (PD₂₀) was 1,001 ± 1,275 μg; the workers received 2.1 ± 2.4 puffs of salbutamol per day. After 3 years, no significant differences in any of the morbidity outcomes (FEV₁, PD₂₀, PEF variability, use of rescue salbutamol, respiratory symptom score) were found as compared with baseline or run-in values.

Conclusions

Regular treatment with inhaled corticosteroids and long-acting bronchodilators seems to prevent respiratory deterioration over a 3-year period in workers with mild-to-moderate persistent OA who were still exposed at work to the environmental cause of their disease.

Section snippets

Subjects

Twenty consecutive subjects with OA (18 men) from inpatients and outpatients referred to the Institute of Occupational Medicine, University of Perugia, Italy, were asked to participate in this study, and all agreed.

OA was diagnosed in all on the basis of a specific bronchoprovocation test result (in 13 subjects) or peak expiratory flow (PEF) monitoring during and after usual work activity (in 7 subjects).¹ Asthmatic reaction after specific exposure was immediate in 6 cases (30.0%), delayed in

Results

Table 1 shows the characteristics, lung function values, PEF variability, PD₂₀, symptom scores, and use of rescue salbutamol at baseline or run-in in the 10 subjects who were followed up for 3 years in their workplace and the 10 subjects who were not. The latter 10 subjects (8 men), left their workplace (6 subjects in the first year, and 4 subjects in the second year). Reasons were reaching the age of retirement (six subjects) and change of job (four subjects, one of whom was made redundant).

Discussion

This prospective 3-year study shows that regular treatment with inhaled corticosteroids and long-acting bronchodilators prevented respiratory deterioration in 10 subjects with OA who were persistently exposed at work to the environmental cause of their disease. In fact, no significant changes in lung function, symptom score, PEF variability, or bronchial hyperresponsiveness were found.

A limitation of this study is the small number of subjects; however, it concurs with recent results of a 1-year

ACKNOWLEDGMENT

We thank Dr. G. A. Boyd for help in reviewing this article, and Stefania Rometta for secretarial assistance.

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Cited by (34)

Bronchial Reactivity and Lung Function After World Trade Center Exposure
2016, Chest
Citation Excerpt :
Occupational airway disease is heterogeneous, including: work-exacerbated asthma (in those with preexisting asthma)27; occupational asthma, which may be immunologic (characterized by a latent period), or irritant-induced27-29; reactive airway dysfunction syndrome (RADS), an acute form of irritant asthma usually associated with single, high-level exposures28,30,31; and occupational COPD.31,32 Prognosis is variable,28 although a substantial fraction of those with occupational asthma may improve after discontinuation of exposure,17-20 or with inhaled corticosteroid therapy, even without discontinuation of exposure.29 Persons with RADS may or may not improve,18,20,30 whereas those with occupational COPD typically do not improve.32
World Trade Center (WTC)-exposed rescue/recovery workers endured massive respiratory insult from inhalation of particulate matter and gases, resulting in respiratory symptoms, loss of lung function, and, for many, bronchial hyperreactivity (BHR). The persistence of respiratory symptoms and lung function abnormalities has been well-documented, whereas persistence of BHR has not been investigated.
A total of 173 WTC-exposed firefighters with bronchial reactivity measured within 2 years after September 11, 2001 (9/11) (baseline methacholine challenge test), were reevaluated in 2013 and 2014 (follow-up methacholine challenge test). FEV₁ measurements were obtained from the late pre-9/11, early post-9/11, and late post-9/11 periods. Respiratory symptoms and corticosteroid treatment were recorded.
Bronchial reactivity remained stable (within 1 doubling dilution) for most (n = 101, 58%). Sixteen of 28 (57%) with BHR (provocative concentration of methacholine producing a 20% decline in FEV₁ <8 mg/mL) at baseline had BHR at follow-up, and an additional 27 of the 145 (19%) without BHR at baseline had BHR at follow-up. In multivariable models, we found that BHR baseline was strongly associated with BHR follow-up (OR, 6.46) and that BHR at follow-up was associated with an estimated 15.4 mL/y greater FEV₁ decline than experienced by those without BHR at follow-up. Annual FEV₁ decline was moderated by corticosteroid use.
Persistent BHR and its deleterious influence on lung function suggest a role for airway inflammation in perpetuation of WTC-associated airway disease. In future massive occupational exposure to inorganic dust/gases, we recommend early and serial pulmonary function testing, including measurements of bronchial reactivity, when possible, and inhaled corticosteroid therapy for those with symptoms or pulmonary function tests consistent with airway disease.
Empowering employers in work-related injuries prevention: A pragmatic trial
2015, Safety Science
Citation Excerpt :
Studies investigating the effectiveness of prevention programs are nonetheless quite scarce. While there is increasing attention by Public Health Services in Italy regarding workplace safety (Arduini and Della Foglia, 1992; Bavazzano et al., 1993; Baldasseroni, 1994; dell’Omo et al., 1998; Gobba et al., 2000; Marabini et al., 2003; Mancini et al., 2005), the few studies that have been published on this topic are not characterized by a high methodological quality (Mattioli et al., 2009). Both experimental and observational studies assessing work-related injury prevention are under investigation and none of the limited number of trials focusing on educational intervention initiatives (Johnston et al., 1994; Burke et al., 2006) were performed using a randomized controlled trial (RCT) design or assessing occupational injury occurrence as their primary outcome.
Interest in work-related injury prevention is increasing, but evaluating workplace safety interventions poses a critical challenge on methodological approaches. The hypothesis has been made that safety training programmes targeting management executives could improve worksite safety. This study aimed to investigate the correlation between a training programme for employers and the rate of occupational injuries in a sample of wood processing industries.
One hundred forty worksites were randomly assigned to the intervention or the control arms of the study. The intervention consisted in a 6 h training course for employers focusing on the benefits, feasibility, and cost-saving connected to safety in the workplace. The primary outcome was the rate of injuries assessed by means of the incidence rate difference (point estimates and 95% confidence interval) in the two arms of the study at the end of the follow-up period.
The rate of work-related injuries decreased in both groups, with an incidence rate after intervention of 3.35 and 3.91 (×10,000 working hours), respectively, in the study and control arms, for a difference of −0.56 (95% CI −1.56–0.45). The reduction in injuries from baseline to the end of the follow-up was comparable to that noted in other geographical areas.
The intervention programme did not appear to have any effect on the decrease in the rate of work-related injuries. We can hypothesize that the training course did not modify employers’ behavior to affect the incidence of occupational injuries.
Evolution of occupational asthma: Does cessation of exposure really improve prognosis?
2014, Respiratory Medicine
Citation Excerpt :
The results of these systematic reviews indicate that the available data on the prognosis of OA are insufficient to enable physicians to provide confident, informed advice to patients with the disease. Probably this conclusion is reached because the majority of the more than 100 papers published so far are heterogeneous single-center studies, with small patient samples and based on a single causative agent; all apply an observational approach and, for ethical reasons, none have randomized patients to avoid or continue exposure to the causative agent [15,16]. The aim of the present study is to assess the evolution of all patients diagnosed with OA in the last ten years at two centers in our country according to the persistence or cessation of exposure to the causative agent and, on the basis of the GINA classification, of asthma severity [17].
To assess the evolution of occupational asthma (OA) depending on whether the patient avoids or continues with exposure to the offending agent.
Study in patients diagnosed with OA using a specific inhalation challenge. Patients underwent the following examinations on the same day: clinical interview, physical examination, forced spirometry, methacholine test and determination of total IgE. Clinical improvement, deterioration or no change were defined according to the changes seen on the GINA severity scale at the time of diagnosis.
Of the 73 patients finally included, 55 had totally ended exposure and 18 continued to be exposed at work. Clinical improvement was observed in 47% of those who had terminated exposure and in 22% of those who remained exposed; clinical deterioration was observed in 14% and 17% respectively (p = 0.805). Logistical regression analysis, including the type of agent and the persistence or avoidance of exposure among the variables, did not show any predictive factors of clinical evolution. Similarly, the changes in FEV₁ and in bronchial hyperresponsiveness were not associated with the avoidance or continuation of exposure to the causative agent.
Avoiding exposure to the causative agent in patients with OA does not seem to improve prognosis in this disease. Despite these findings, there is insufficient evidence to recommend a change in current management guidelines.
Work-Related Asthma: A Case-Based Approach to Management
2011, Immunology and Allergy Clinics of North America
Citation Excerpt :
The medical literature is inconsistent regarding the long-term outcomes of continued but reduced exposure to HMW allergens in workers with HMW OA compared with LMW OA, in which continued exposure usually leads to worsened disease. One small study following 10 workers with OA who were treated for asthma and remained in exposure showed no significant differences in lung function, use of rescue bronchodilator, or respiratory symptom scores over 3 years.16 Two separate studies found similarly good outcomes in workers sensitized to natural rubber latex who were removed from exposure and those who remained in their jobs but greatly reduced their latex exposure through switching to nonlatex gloves while coworkers changed to low-protein powder-free latex gloves.17,18
The diagnosis and management of occupational asthma
2008, Revue des Maladies Respiratoires
L’asthme professionnel avec période de latence induite après des expositions répétées, se caractérise par une sensibilisation immunologique à l’agent responsable pouvant être IgE- dépendante, et une hyperréactivité bronchique non spécifique.
L’interrogatoire est un élément capital des investigations de l’asthme professionnel. Les éléments évocateurs sont la survenue de symptômes en période de travail et l’amélioration durant les congés. Ce dernier facteur a le meilleur niveau de preuve (grade 2+) lors de l’analyse de plusieurs publications selon les critères de médecine basés sur les preuves. L’étude du poste de travail est fondamentale, basée sur la coopération avec le médecin du travail. Des résultats positifs du bilan immunologique (tests cutanés et/ou recherche d’IgE spécifiques) associés à des critères objectifs de symptômes en relation avec le travail (modification du DEP, des EFR et/ou de l’HRBNS) permettent de préciser le diagnostic étiologique de l’asthme professionnel. Les tests de provocation bronchique spécifique nécessitant des équipes entraînées, apportent la preuve de la responsabilité de nouvelles substances et sont un recours nécessaire lorsque les autres investigations ne sont pas disponibles ou sont discordantes. L’asthme professionnel nécessite une démarche par étapes successives dans lesquelles peuvent également s’intégrer la recherche d’éosinophiles dans l’expectoration et la mesure du NO exhalé.
L’asthme professionnel nécessite une éviction du milieu du travail car la persistance de l’exposition peut entraîner une aggravation progressive de l’asthme et sa pérennisation. Cependant, l’éviction professionnelle a souvent des conséquences sociales et financières délétères, ce qui peut autoriser d’envisager un compromis avec une réduction de l’exposition par différents aménagements accompagnés d’un traitement adapté. Le traitement de l’asthme professionnel ne diffère pas de celui de l’asthme en général, il doit être ajusté selon les critères de gravité en utilisant bronchodilatateurs et corticoïdes. Sur le plan médico-légal, l’asthme professionnel peut être reconnu après déclaration en maladie professionnelle. En France, l’asthme est mentionné dans plusieurs tableaux de maladie professionnelle.
M.-C. Kopferschmitt-Kubler, E. Popin, G. Pauli
Occupational asthma (OA), with a latency period induced by multiple exposures, is characterized by immunological sensitization to the responsible agent, based on both an IgE mediated mechanisms and non specific bronchial hyper responsiveness.
In the diagnosis of OA, the medical history is obviously the starting-point. Onset of respiratory symptoms at work and resolution on vacation are indications of the diagnosis. After analysis of several publications, this element appears to have the best level of proof (grade 2+) according to the criteria of evidence-based medicine. A visit of the workplace, with the cooperation of the industrial physician, is essential to characterize the nature of the exposure. Positive immunological tests (skin tests and/or specific IgE) associated with objective criteria of symptoms related to work (modification of PEFR, lung function and/or nonspecific bronchial hyper responsiveness) will confirm the aetiological diagnosis of OA. Specific bronchial provocation tests performed in the laboratory allow the identification of new agents involved in OA and are necessary when other investigations are discordant or unavailable. OA needs a stepwise approach including induced sputum eosinophilic counts and measurements of exhaled nitric oxide.
requires removal from the workplace because persistence of exposure to respiratory sensitisers may lead to an increase and prolongation of asthma symptoms. However, removal from the workplace can have tremendous professional, financial and social consequences, and sometimes a compromise must be found with reduction of exposure by various methods combined with adequate treatment. The pharmacological treatment of patients with OA should be the same as for patients with non OA, the use of bronchodilators and corticoids depending on the severity of asthma. Concerning the medico-legal aspects, OA can be recognised as an occupational disease. In France OA is included in several tables of work-related diseases.
Making the Diagnosis of Occupational Asthma: When to Suspect It and What to Do
2008, Primary Care - Clinics in Office Practice
Citation Excerpt :
The pharmacologic management of occupational asthma is identical to nonoccupational asthma [44]. Treatment with inhaled corticosteroids, while attempting to keep the worker in his or her job, can stabilize disease in some patients [45,46]. In this case, close follow-up and frequent monitoring of patient lung function is mandatory.
Although most adult patients seen by a clinician are employed, medical school curricula and residency training rarely cover occupational exposures and resultant diseases, even common ones that are encountered in a typical medical practice. This primer on occupational asthma is intended for the primary care clinician to provide the essential tools to diagnose and treat airways disease in the workplace. Using a case vignette format, we review the basic approach to suspecting and establishing a diagnosis of occupational asthma and address the thornier question of what to do about it. After reviewing this primer, the reader will be able to routinely include occupational asthma as part of the differential diagnoses in the adult patient with new or worsened asthma.

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: Financial support was provided by ISPESL.

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Chest

Study objective

Methods

Measurements and results

Conclusions

Section snippets

Subjects

Results

Discussion

ACKNOWLEDGMENT

References (23)

Clinical features and natural history of occupational asthma due to Western red cedar (Thuja plicata)

Am J Med

Follow-up of occupational asthma caused by crab and various agents

J Allergy Clin Immunol

Occupational asthma due to various agents: absence of clinical and functional improvement at an interval of four or more years after cessation of exposure

Chest

Consequences of occupational asthma

Respir Med

Clinical and socioeconomic features of subjects with red cedar asthma: a follow-up study

Chest

Occupational asthma: a longitudinal study on the clinical and socioeconomic outcome after diagnosis

Chest

Management of occupational asthma

Eur Respir J

Prognosis of occupational asthma

Eur Respir J

Fate of occupational asthma and follow-up study of patients with occupational asthma due to Western red cedar (Thuja plicata)

Am Rev Respir Dis

Occupational asthma in electronic workers caused by colophony fumes: follow-up of affected workers

Thorax

Cited by (34)

Bronchial Reactivity and Lung Function After World Trade Center Exposure

Empowering employers in work-related injuries prevention: A pragmatic trial

Evolution of occupational asthma: Does cessation of exposure really improve prognosis?

Work-Related Asthma: A Case-Based Approach to Management

The diagnosis and management of occupational asthma

Making the Diagnosis of Occupational Asthma: When to Suspect It and What to Do

Chest

Occupational and Environmental Lung DiseaseOutcome of Occupational Asthma in Patients With Continuous Exposure: A 3-Year Longitudinal Study During Pharmacologic Treatment

Study objective

Methods

Measurements and results

Conclusions

Section snippets

Subjects

Results

Discussion

ACKNOWLEDGMENT

Am J Med

J Allergy Clin Immunol

Chest

Respir Med

Chest

Chest

Management of occupational asthma

Eur Respir J

Prognosis of occupational asthma

Eur Respir J

Fate of occupational asthma and follow-up study of patients with occupational asthma due to Western red cedar (Thuja plicata)

Am Rev Respir Dis

Occupational asthma in electronic workers caused by colophony fumes: follow-up of affected workers

Thorax

Occupational and Environmental Lung Disease
Outcome of Occupational Asthma in Patients With Continuous Exposure: A 3-Year Longitudinal Study During Pharmacologic Treatment