Reduction of exposure in the management of occupational asthma

The management of immunologically mediated occupational asthma may be difficult in clinical practice since complete avoidance of exposure to the sensitizing agent is associated with a substantial adverse socio-economic impact. The purpose of this review was to critically analyze the available information on the effectiveness of reducing exposure as an alternative to complete avoidance.

Short-term exposure studies showed that respiratory protective devices can reduce bronchial responses to sensitizing agents in patients with occupational asthma, but do not provide complete protection. Recent systematic reviews of long-term follow-up studies of workers with occupational asthma indicated that reduction of exposure to the causal agent is associated with a lower likelihood of improvement in asthma symptoms and a higher risk of worsening of symptoms and nonspecific bronchial hyper-responsiveness. There are insufficient data to compare the socio-economic consequences related to both of these management options.

Available data indicate that a reduction of exposure to the agents causing occupational asthma cannot be routinely recommended as an alternative to complete avoidance. However, due to the methodological weaknesses of the published studies, further investigations are required to determine the evidence-based cost-effectiveness of the occupational asthma management strategies.