Occupational exposure to substances that trigger Asthma can affect the severity of the disease, according to a report from France.

Previous studies have identified workplace exposures as risk factors for Asthma and for disease flare-ups, but it was unclear if such exposures were also tied to Asthma severity.

In the present study, in the American Journal of Respiratory and Critical Care Medicine, Dr. Nicole Le Moual, from the National Institute for Health and Medical Research in Villejuif, and colleagues analyzed data from 148 adults with asthma and from 228 unaffected “control” subjects to assess the impact of occupational exposures on asthma severity.

Workplace exposure to asthma-triggering substances (“asthmogens”) and to non-asthma-causing irritants was determined with an asthma-specific job exposure matrix. Exposure to any occupational asthmogen was tied to an increased risk of severe Asthma - with the increase in risk ranging from 3.7-fold to 7.5-fold.

By contrast, no significant associations were seen between non-asthma-causing irritant exposure and asthma severity.

“Occupational asthma should be excluded in every subject with recent onset of adult asthma,” Dr. Jean-Luc Malo, from Sacre-Coeur Hospital in Montreal, advises in a related editorial. “There is indeed a possibility of curing asthma in this instance.”

SOURCE: American Journal of Respiratory and Critical Care Medicine, August 15, 2005.