Work-exacerbated asthma related to ammonia, solvents, exhaust, silica and aerosols

Work-exacerbated asthma is defined in Quebec as Pre-existing or co-incident asthma  that is exacerbated by work-related stimuli and in whom specific challenge tests are negative. The papers compared occupational asthma with positive challenges with WEA. It is however unclear whether the WEA group had SIC to the agents descibed including ammonia, vehicle exhaust, mineral fibres, silica and aerosols, exposure to which was more common in the WEA group. All had asthma with either significant bronchodilator reversibility of a positive methacholine test (<8mg/ml).  Interestingly a similar proprtion (OA 24% and WEA 21%) had a history of asthma before the current exposures, requiring the onset of asthma to be coincidental in 79% of those with WEA.

References

	Lemiere C, Bégin D, Camus M, ForgetA, Boulet L-P, Gérin M , Occupational risk factors associated with work-exacerbated asthma in Quebec, Occup Environ Med, 2012;69:901-907,

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