Occupational asthma: irritant-induced

This talk will focus on irritant-induced asthma. Asthma associated with either acute or chronic exposures to irritants and low molecular weight chemicals is usually difficult to diagnose. Prick tests and specific IgE are seldom useful. Thus, finding the correct diagnosis is often difficult and depends on a precise history, exclusion of other disorders, lung function tests, measures of bronchial hyperreactivity and, occasionally, specific bronchial provocation. In the introduction a brief history of irritant-induced asthma will be reviewed. Irritant-induced asthma and reactive airway dysfunction syndrome (RADS) will be defined. RADS develops minutes or hours after a single accidental inhalation of high concentrations of irritant gas, aerosol or particles and is followed by asthma-like symptoms and bronchial hyperreactiviity for a prolonged period. Irritant-induced asthma is a more general term an asthmatic syndrome after single or multiple irritant exposure. Experimental models  and possible mechanisms of  irritant-induced asthma will be discussed.  The epidemiology of irritant-induced asthma will be reviewed with emphasis on the more frequent causes, e.g. acid fumes, chlorine, cleaning agents and isocyanates.     Diagnostic criteria will be reviewed. Relevant cases will be presented and discussed.