Occupational and work-exacerbated asthma: similarities and differences.

Over the years, there have been tremendous efforts to improve the understanding of occupational asthma (OA), whereas work-exacerbated asthma (WEA) has been somewhat overlooked. The aim of this work is to review the literature, comparing the prevalence of OA and WEA, their clinical and inflammatory characteristics, as well as the work environment of those suffering from OA and WEA. We performed a PubMed search up to September 2006 using the keywords: work-related asthma, WEA, work-aggravated asthma and OA. Only studies in English were included for consideration. We found that OA and WEA are prevalent conditions. The characteristics of subjects with OA and WEA vary according to the type of studies undertaken to describe these conditions. Many sensitizing agents have been reported to cause OA, whereas exposures to irritant agents seem to be associated with the occurrence of WEA. The inflammatory profile may differ between these two conditions, but the data are too limited and sometimes too contradictory to allow a firm conclusion to be drawn. The socioeconomic outcome of these conditions seems similar. Therefore, further studies investigating the prevalence of WEA, as well as its clinical, functional and inflammatory characteristics, are needed to improve the management of the workers with WEA.