Table 3.
Non-WRA | Sensitizer-Induced OA | Irritant-Induced OA |
---|---|---|
Allergens | ||
Variable exposure over time. | Variable exposure over time. | |
Inhalation of allergens on particles. | ||
Absorption from skin exposure can cause sensitization but not asthma. | Absorption from skin exposure may cause sensitization but not asthma. | |
Levels of exposure are an important risk factor. | Levels of exposure are an important risk factor. | |
Highest levels of exposure can lead to decreased sensitivity. | Risk is present even at low levels of exposure to high-molecular-weight and low-molecular-weight agents: a pragmatic approach is to aim for an excess risk below a certain percentage. | |
Irritant Exposures Inducing Asthma | ||
Acute irritant high-level exposure. | Acute irritant high-level exposure. | |
Recurrent exposures to nonmassive levels. | Recurrent exposures to nonmassive levels. | |
Long-term low exposures. | Long-term low exposures. | |
Irritant exposures may have an adjuvant effect, increasing IgE-mediated responses (e.g., diesel exhaust). | Irritant exposures may have an adjuvant effect, increasing IgE-mediated responses (e.g., diesel exhaust). | Irritant exposures may have an adjuvant effect, increasing IgE-mediated responses (e.g., diesel exhaust). |
Ascertaining exposures can be complex and can vary over time (e.g., cleaning agents). | Ascertaining exposures can be complex and can vary over time (e.g., cleaning agents). | |
Gene–environment interactions can occur. | Gene–environment interactions can occur. | Gene–environment interactions can occur. |
Allergens and Irritants | ||
Exposure controls may reduce risks of asthma onset and exacerbations. | Exposure controls may reduce risks of asthma onset and exacerbations. | Exposure controls may reduce risks of asthma onset and exacerbations. |
Definition of abbreviations: OA = occupational asthma; WRA = work-related asthma.
Similarities are printed in bold. Features that differ or have only been only evaluated for one condition are not bold.