Provocation studies in the diagnosis of occupational asthma

The list of occupational allergens grows longer each year as new products and substances are reported by industries, ranging from pharmaceutical to automobile manufacturing companies, to be causative agents of occupational asthma (OA). The identification of an agent that causes OA has medical, legal, and financial consequences for employers and employees. The diagnosis of OA and identification of the offending agent should be undertaken in a careful, methodical, and objective manner. This article focuses on nonspecific and specific bronchial challenge testing for identification of OA triggers.