Investigation of occupational asthma.

Occupational asthma is one of the most frequent lung diseases related to work. It is defined as asthma causally and specifically related to exposure to airborne dusts, gases, vapours or fumes in the working environment. Because occupational asthma may cause long-lasting disability, it is important to identify affected workers correctly and to remove them as soon as possible from the sensitizing agent. Although history is the clue to the diagnosis, it is not sensitive nor specific enough, and the diagnosis should be confirmed by objective means. This article reviews the different steps (with their advantages and disadvantages) involved in making the diagnosis: history, confirmation of the diagnosis of asthma, work visit, skin tests and serology, monitoring of peak expiratory flows and nonallergic bronchial responsiveness. The gold standard remains specific inhalation challenges in the laboratory or at work.