From the Research
No, irritants causing direct cell damage and inflammation do not account for most cases of occupational asthma. Most occupational asthma cases are actually caused by an immunologic mechanism involving sensitization to specific workplace allergens, rather than direct irritant effects 1. In this immunologic form, workers develop specific IgE antibodies to workplace substances after a latency period of exposure, leading to typical allergic asthma symptoms upon re-exposure. The less common form, irritant-induced occupational asthma (including Reactive Airways Dysfunction Syndrome or RADS), occurs from high-level exposure to irritating chemicals, gases, or fumes that directly damage the airways without requiring prior sensitization. This distinction is important clinically because management differs between the two types - sensitizer-induced asthma typically requires complete removal from the causative agent, while irritant-induced cases may sometimes be managed with reduced exposure and medication 2. The predominance of the immunologic mechanism explains why identification of specific workplace allergens and implementation of appropriate exposure controls are central to occupational asthma prevention strategies. Some studies have reported that occupational factors have been implicated in 9 to 15% of all cases of adult asthma, and more than 400 agents causing occupational asthma are known 3. However, the most recent and highest quality study, published in 2020, still supports the idea that most occupational asthma cases are caused by an immunologic mechanism, rather than direct irritant effects 1. Therefore, identification of specific workplace allergens and implementation of appropriate exposure controls are crucial in preventing occupational asthma. Key points to consider in the management of occupational asthma include:
- Early and accurate diagnosis of occupational asthma through comprehensive testing 1
- Removal of the worker from exposure to the causal agent 2
- Treatment with inhaled glucocorticoids 4
- Implementation of strategies for preventing occupational asthma, including identification of specific workplace allergens and implementation of appropriate exposure controls 3.