Occupational asthma

Occupational asthma (OA) should be suspected in all adult patients with asthma.

Occupational history may identify work-related causes. Details of work exposures should be obtained from material safety data sheets available to the patient from their workplace.

Objective evidence of asthma should be obtained from spirometry, a bronchodilator response, and/or a methacholine challenge. Tests should be performed when the patient is symptomatic and/or within days of exposure to a suspected aetiological agent.

In sensitiser-induced OA, removal from any further exposure to that agent is recommended if an immunological response to the work sensitiser is demonstrated by skin or in vitro tests.

In irritant-induced OA, preventive measures should be implemented in the workplace to reduce future exposures and episodes.

For all causes of OA, the clinician should continue treating the asthma as appropriate, assist in the initiation of any appropriate compensation claim, and consider other workers at risk.

OA is asthma caused by the workplace and may result from immunological or non-immunological stimuli.[1]Cullinan P, Vandenplas O, Bernstein D. Assessment and management of occupational asthma. J Allergy Clin Immunol Pract. 2020 Nov-Dec;8(10):3264-75. http://www.ncbi.nlm.nih.gov/pubmed/33161958?tool=bestpractice.com ​

Sensitiser-induced OA is caused by immunological stimuli and develops after a latency period between first exposure and the onset of symptoms.[2]Tarlo SM, Lemiere C. Occupational asthma. N Engl J Med. 2014 Feb 13;370(7):640-9. http://www.ncbi.nlm.nih.gov/pubmed/24521110?tool=bestpractice.com [3]Malo JL, Vandenplas O. Definitions and classification of work-related asthma. Immunol Allergy Clin North Am. 2011 Nov;31(4):645-62. http://www.ncbi.nlm.nih.gov/pubmed/21978849?tool=bestpractice.com ​ Irritant-induced OA (including reactive airways dysfunction syndrome) is caused by non-immunological stimuli.[4]Vandenplas O, Wiszniewska M, Raulf M, et al. EAACI position paper: irritant-induced asthma. Allergy. 2014 Sep;69(9):1141-53. http://onlinelibrary.wiley.com/doi/10.1111/all.12448/full http://www.ncbi.nlm.nih.gov/pubmed/24854136?tool=bestpractice.com