Management of occupational asthma: cessation or reduction of exposure? A systematic review of available evidence

Abstract

Reduction of exposure to sensitising agents causing occupational asthma has been proposed as an alternative to total avoidance in order to minimise the adverse socio-economic impact of the condition.The aim of this systematic review was to compare the effects of these two management options on asthma and socio-economic outcomes.A bibliographic search was conducted to identify studies examining the outcome of workers with occupational asthma after reduction or cessation of exposure to the causal agent.The changes in asthma symptoms and nonspecific bronchial hyperresponsiveness after reduction or cessation of exposure were described in nine and five studies, respectively. The meta-analysis of pooled data showed that a reduction of exposure was associated with a lower likelihood of improvement (OR 0.16, 95% CI 0.03-0.91) and recovery (OR 0.30, 95% CI 0.11-0.84) of asthma symptoms and a higher risk of worsening of the symptoms (OR 10.23, 95% CI 2.97-35.28) and nonspecific bronchial hyperresponsiveness (OR 5.65, 95% CI 1.11-28.82), compared with complete avoidance of exposure.This systematic review indicates that reduction of exposure cannot be routinely recommended as an alternative to cessation of exposure in the management of occupational asthma. However, further investigations are required before drawing evidence-based conclusions on the costeffectiveness of this approach.

Guidelines for the management of work-related asthma

“…The pooled odds ratio (based on available individual studies) was calculated for each outcome after reduction or cessation of exposure using a random-effect model because heterogeneity between studies was observed. Full details about the methodology used are given elsewhere [35].…”

“…However, in the underlying studies, the exposure was not monitored objectively. Thus, it is not known to what extent the exposure was truly reduced and whether the derived exposure reduction can be regarded as substantial [35].…”

Human Mesenchymal Stem Cells Resolve Airway Inflammation, Hyperreactivity, and Histopathology in a Mouse Model of Occupational Asthma

“…Nowadays, management of OA is largely preventive and symptomatic, aimed avoiding or reducing work exposure to the causative agent and optimizing the standard medical treatment with bronchodilators and inhaled glucocorticoids [5]. Nevertheless, pharmacological treatment has proven of limited utility [6].…”

When Should Specific Occupational Challenge Tests Be Performed?

“…OSA is also associated with systemic infl ammation with elevations in tumor necrosis factor-a and IL-6 levels. 2 , 3 The ability of CPAP to reduce local infl ammation 3 or other factors related to repeated hypoxemia and hypercarbia might also play a role. 4 OSA is associated with sleep disruption and nocturnal arousals, which contribute to elevated sympathetic activation.…”