Chest
Clinical Investigations: AsthmaFollow-up of Occupational Asthma After Removal From or Diminution of Exposure to the Responsible Agent: Relevance of the Length of the Interval From Cessation of Exposure
Section snippets
Study Design
Every subject was evaluated on two separate visits. The first visit took place at the time of diagnosis of OA. Patients were then referred by either the Quebec Workers' Compensation Board or by the treating physician. A questionnaire, assessment of spirometry and bronchial responsiveness to methacholine, and skin prick tests with ubiquitous inhalants were performed at the time the diagnosis was confirmed (see below). The same procedures were performed at the second visit. The follow-up
Results
Forty-one of 99 subjects (41%) were receiving inhaled steroids at the follow-up visit (Table 2), while 49 subjects (50%) had been receiving inhaled steroids for >6 months between the two visits (not shown). One third of subjects had an abnormal FEV1 value. There were no significant changes in mean results for FEV1 or in the number of subjects with abnormal FEV1 values between the two visits (Table 2). One third of subjects had a normal level of PC20 at the follow-up visit. There was a
Discussion
Our study examined the outcome of subjects with OA after removal from exposure with a specific focus on the importance of the duration since exposure stopped. Along with findings previously published,3,4,6 we showed that the level of bronchial responsiveness at the time of diagnosis, a factor that reflects the severity of asthma, and the duration of exposure are predictors of the persistence of bronchial hyperresponsiveness. Moreover, for the first time (to our knowledge), we showed that the
Acknowledgments
The authors thank Lori Schubert for examining the manuscript and the reviewers for their very constructive and helpful criticisms.
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Long-Term Follow-Up of Cluster-Based Diisocyanate Asthma Phenotypes
2021, Journal of Allergy and Clinical Immunology: In PracticeCitation Excerpt :Our study cannot shed light on this topic owing to the low number of workers with continued exposure. Our patients exhibited a lower degree of bronchial hyperreactivity at follow-up than at diagnosis, which is in agreement with previous investigations.22,23 The rate of recovery of the disease in our cohort (28.5%) is also in accordance with previous OA studies,22,24 and is higher than that detected (15%) in adult-onset asthma (≥20 years) in a large Italian cross-sectional study.25
Evolution of occupational asthma: Does cessation of exposure really improve prognosis?
2014, Respiratory MedicineCitation Excerpt :Occupational asthma (OA) is the most frequent work-related respiratory disease in developed countries [1,2] and it is estimated that roughly 10% cases of bronchial asthma and between 15 and 25% of adult onset asthma may be of occupational origin [3,4]. For workers with OA caused by a respiratory sensitizer, complete and definitive removal from exposure to the sensitizing agent has usually been recommended as the most efficient therapeutic approach [5–9]. However, bearing in mind that cessation of exposure is often not feasible [10], in recent years a number of meta-analyses have been carried out to compare the effects of these two management options [11–14].
Longitudinal assessment of spirometry in the world trade center medical monitoring program
2009, ChestCitation Excerpt :Respiratory symptoms and bronchial hyperresponsiveness have lasted for years in some workers with RADS. Excessive FEV1 declines have been reported following large, short-term exposures or repetitive lower level exposures to several types of respiratory irritants and sensitizers,27,33 even without further exposure.34–36 We speculate based on our results that smokers in our WTC-exposed cohort may have been more likely to have fixed airway dysfunction than nonsmokers.
Occupational Exposures and Adult Asthma
2008, Immunology and Allergy Clinics of North AmericaCitation Excerpt :Follow-up studies of workers who have sensitizer-induced OA have reported improvement in asthma symptoms, medication needs, and airway responsiveness to methacholine in a subset after removal from exposure to the relevant work sensitizer. Outcome, as reported in some studies, is better in patients who had initial milder asthma at the time of removal from exposure and a shorter duration of asthma at the time of removal [45,46]. Duration of follow-up and the reported results are not uniform between studies, however, and one systematic review concludes that the studies were not sufficiently uniform for formal analyses although plotting of results suggested improvement from removal as compared with reduced or continuing exposure [47].
Making the Diagnosis of Occupational Asthma: When to Suspect It and What to Do
2008, Primary Care - Clinics in Office PracticeCitation Excerpt :Natural history studies in snow crab processing workers with occupational asthma show that the FEV1 continues to improve over a year out of exposure before a plateau, and the reduction in bronchial hyperresponsiveness takes even longer [62]. More recent studies on patients with occupational asthma from a variety of exposures confirm that bronchial hyperresponsiveness improves most significantly in the first 2.5 years out of exposure, but can demonstrate continued, although slower, improvement for many years thereafter [63,64]. The key message is that although cure is possible with removal from exposure early in the course of disease, most patients have persistent asthma requiring ongoing medical treatment and follow-up.
Comparison of high- and low-molecular-weight sensitizing agents causing occupational asthma: an evidence-based insight
2024, Expert Review of Clinical Immunology
This study was partly funded by the Centre québécois d'excellence en santé respiratoire.