Occupational asthma is defined as "a disease of variable airflow limitations and/or airway hyper-responsiveness due to causes and conditions attributable to a particular occupational environment and not stimuli that are being encountered outside the workplace." An analysis of general population-based studies published up to 2007 showed that 17.6% of all adult-onset asthma is due to workplace exposures. In this article, Different aspects of occupational asthma are briefly reviewed.

Several studies reported the appearance of asthma and autoimmune conditions in the same patient, but the clinical significance of this association was not yet assessed.One hundred asthmatic patients were observed for one year evolution with death, severe exacerbations, intake of > 1000 micrograms of beclometasone or equivalent (high ICS) and FEV1 decline >100 ml, in relation with ANA (ELISA), sputum and blood eosinophilia (EO), NSAID intolerance, BMI >25, chronic rhinosinusitis, smoking status and FEV1 <30% predicted (low FEV1).After 1 year of observation, there were 5 deaths, 28 severe asthma exacerbations requiring hospitalisations, 24 cases requiring high inhaled corticosteroid intake, and 19 patients with fast FEV1 decline (>100 ml/year). Multiple regression analysis pointed out several different independent risk factors for severe asthma evolution: for death presence of ANA (P=0.037), NSAID intolerance (P<0.001) and low FEV1 (P=0.021); for evolution with severe exacerbations ANA (p=0.011), sputum EO (P<0.001), smoking (P=0.044) and NSAID intolerance (P=0.022); for high ICS intake ANA (P=0.036), sputum EO (P=0.026) and low FEV1 (P=0.006); for FEV1 decline >100 ml ANA (P=0.006), sputum EO (P=0.037), BMI>25 (P=0.046) and NSAID intolerance (P=0.017).The presence of ANA is an independent risk factor in asthma for evolution with death, severe exacerbations, high inhaled corticosteroid intake and FEV1 decline >100 ml.