Epidemiology

Contemporary evidence regarding the epidemiology of occupational asthma (OA) is limited.[5]

In the US, the incidence of OA is estimated to be 179 per million people per year.[6][7]​​​ The estimated incidence is 20 to 40 per million people per year in the UK, and 187 per million per year in Finland.[8][9][10]​​​ Differences in OA incidence may relate to variability in local industries, diagnostic criteria, and sources used to generate data, such as workers’ compensation sources, surveillance programs, or population studies.

​Approximately 13% to 16% of asthma in industrialized (or rapidly industrializing) countries can be attributed to occupational exposures.[11][12]​​​ In Zambia, a less industrialized country, only 6% of adult patients diagnosed with asthma were found to have OA.[13]​​

In Europe, incidence of OA has declined in recent decades.[14][15][14]​​ This trend is consistent with European initiatives to address exposures relevant to occupational asthma.[16]

The sex distribution of OA is mostly due to differences in occupations and, therefore, exposures experienced.[17]​ Greater exposure to cleaning products, textiles, and biologic agents is reported in women. In contrast, men have a reported increased risk of asthma associated with flour and welding fumes.

Risk of OA is occupation- and exposure-dependent

Commonly reported at-risk occupations include animal health technology, health care, baking, car painting, nursing, woodwork, cleaning, and hairdressing.[8][9][10][18][19]​​​[20][21][22][23]

Sensitizer-induced OA (caused by immunologic stimuli) accounts for a significantly greater proportion of all cases of OA than irritant-induced OA (caused by nonimmunologic stimuli). More than 300 causes of sensitizer-induced OA have been reported.[24][25]​​​ In some studies about 90% of all OA is attributed to sensitizer-induced OA.[26]​ In 2014-2018, in the UK, incidence of irritant-induced OA has been estimated to be 0.56 per million employed per year.[27]

Globally, the commonest causes of OA are diisocyanates and flour.[28][29][30]​​ In North America, exposure to western red cedar is an important cause.[31]​ Reports indicate that cannabis production may be associated with respiratory tract symptoms, including OA.[32][33]

Many cases of irritant-induced asthma are related to corrosive acid or alkaline chemicals.[34]​ Acute symptomatic inhalation events such as fire, mixing of cleaning products, and chemical spills are associated with excess asthma risk.[9]

Use of this content is subject to our disclaimer