title: 8. Occupational asthma and allergies.
abstract: A diversity of airborne dusts, gases, fumes, and vapors can cause dose-related symptoms in individuals exposed in the workplace. More than 250 chemicals have been incriminated as a cause of occupational asthma (OA). The prevalence of OA ranges from 2% to 6% of the asthmatic population. Predisposing factors facilitating the development of OA include the work environment, climatic conditions, genetic proclivities, tobacco and recreational drug use, respiratory infection, and bronchial hyperresponsiveness. Pathogenetically, new-onset OA may be immunologic or nonimmunologic in origin. The immunologic variants are usually caused by high molecular-weight allergens such as grain dust and animal or fish protein. Symptoms ensue after a latent period of months to years. Nonimmunologic OA can be precipitated by a brief, high-level exposure to a potent irritant. Symptoms occur immediately or within a few hours of the exposure. In either instance, once the diagnosis is established, the worker should be removed from the workplace. If the diagnosis is made in a timely fashion, most workers experience improvement. Prevention is the best therapeutic intervention.
authors.affiliation: Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, OP34, Portland, OR 97201-3098, USA.
authors.forename: Emil J
authors.initials: EJ
authors.lastname: Bardana
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000628:therapy; D003937:Diagnosis, Differential; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000628:therapy; D015994:Incidence; D009784:Occupational Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000628:therapy