Sensitisation of severe asthma in different occupations: A multicentre study in China

Objective This was the first multicentre study assessing the sensitisation patterns in patients with severe asthma by different occupations as well as different regions of China, and aimed to provide evidence for the prevention of sensitised patients with severe asthma. Methods A total of 676 adults were included and assigned to three cohorts. Cohort A was comprised of severe asthma patients without smoking (n = 454), cohort B comprised severe asthmatic patients who were ex-smokers (n = 149), and cohort C comprised non-asthma individuals (n = 73). All study subjects underwent testing of serum sIgE level of house dusts mix (hx2), foods mix (fx5), moulds mix (mx2), tree pollen mix (tx4) and weed pollen mix (wx5) simultaneously. Results Overall, the positive rates of hx2, fx5, mx2, tx4 and wx5 were 37.6%, 11.9%, 16.6%, 9.0% and 9.5% in severe asthmatic patients, respectively. Comparing cohort A with cohort B, the hx2 positive rates in cohort A were higher in fulltime homemaker (30.0% vs. 0.0%) and medical staff (40.0% vs. 0.0%,P < 0.05). However, the mx2 positive rates in cohort B were higher in businessman (30.0% vs. 7.0%) and the tx4 positive rates in cohort B were higher in drivers (35.7% vs. 0.0%,P < 0.05). The optimal scale analysis showed that severe asthmatic patients who work indoor were more prone to be allergic to house dusts (Cronbach's alpha = 76.4%). Conclusion Patients with severe asthma in different occupations exhibited different sensitisation patterns. Avoid being contact with house dust and application of indoor air purifier should be considered for severe asthma patients.