Work aggravated asthma; a review of the recent evidence.

BACKGROUND: The link between asthma and inhaled workplace exposures has been long appreciated, and yet aggravation of asthma symptoms by work conditions, known as work-aggravated asthma (WAA), remains relatively common. SOURCES OF DATA: A review of the literature published over the last 3 years was carried out, and additional key articles were included from outside this timeframe. AGREEMENT: WAA is commonly reported by workers with asthma. One published assessment of 12 studies identified a median prevalence of 21.5% among workers with asthma. Commonly reported causes included a variety of inhaled dusts, smoke, vapours, fumes, gases and mists, common and workplace-specific aeroallergens, physical environmental factors including temperature and humidity and physical activity at work. CONTROVERSY: Remains in relation to definition, and how to distinguish WAA from occupational asthma in which there is sensitization to an agent in the workplace. Both these areas, and the development of workplace interventions to reduce WAA, are timely topics for future research.