Abstract
Occupational asthma (OA) and work-exacerbated asthma (WEA), collectively known as
work-related asthma (WRA), have been recognized as the most prevalent work-related lung diseases in the
industrialized world. OA is asthma caused by workplace conditions, and is subdivided
into sensitizer-induced (allergic) OA and irritant-induced (nonallergic) OA. WEA is
asthma that is made worse, but was not initially caused, by workplace conditions.
Although WRA is rarely fatal, patients with WRA frequently experience excessive time
lost from work, workplace-specific severe disability, loss of income, job loss, and
related psychosocial and financial problems. More than 400 workplace environmental
agents have been reported to cause WRA, and are classified by molecular weight and
allergenic and irritant properties. Diagnosis of WRA requires confirmation of a diagnosis
of asthma plus evidence that the asthma was caused or worsened by workplace conditions.
Accuracy of diagnosis is important because either overdiagnosis or missed diagnosis
of WRA can be problematic for the patient. Self-reported clinical symptoms alone have
only fair sensitivity and specificity for OA. If possible, diagnostic assessment should
also include objective evidence with functional and immunologic testing. Treatment
and prevention of onset or worsening of WRA can be highly effective and typically
include both optimal medical management (generally the same as for non-WRA) and, importantly,
avoidance of sensitizer or irritant exposures that caused or exacerbate the asthma.
In most cases of OA, prognosis is better with cessation rather than reduction of exposure,
and this may require substantial changes in the workplace environment or change of
job or even profession.
Keywords
occupational asthma - work-exacerbated asthma - work-related asthma - irritant-induced
asthma - peak expiratory flow - nonspecific bronchial hyperresponsiveness - diagnosis
- sensitivity - specificity - prevention
