The fifth Jack Pepys Workshop on
Asthma in the Workplace focused on the similarities and differences of work-related
asthma (WRA) and non-work-related
asthma (non-WRA). WRA includes
occupational asthma (OA) and work-exacerbated
asthma (WEA). There are few biological differences in the mechanisms of sensitization to environmental and occupational
allergens. Non-WRA and OA, when due to high-molecular-weight agents, are both
IgE mediated; it is uncertain whether OA due to low-molecular-weight agents is also
IgE mediated. Risk factors for OA include female sex, a history of upper airway symptoms, and a history of bronchial hyperresponsiveness. Atopy is a risk factor for OA due to high-molecular-weight agents, and exposure to cleaning agents is a risk factor for both OA and non-WRA. WEA is important among workers with preexisting
asthma and may overlap with
irritant-induced
asthma, a type of OA. Induced sputum cytology can confirm airway
inflammation, but specific inhalation challenge is the reference standard diagnostic test. Inhalation challenges are relatively safe, with the most severe reactions occurring with low-molecular-weight agents. Indirect health care costs account for about 50% of total
asthma costs. Workers with poor
asthma control (WRA or non-WRA) are less likely to be employed. Income loss is a major contributor to the indirect costs of WRA. Overall,
asthma outcomes probably are worse for adult-onset than for childhood-onset
asthma but better for OA than adult-onset non-WRA. Important aspects of management of OA are rapid and proper confirmation of the diagnosis and reduction of exposure to sensitizers or irritants at work and home.