[Occupational asthma].

Occupational asthma is an entity caused by conditions deriving from a certain work milieu and not from stimuli found outside the workplace. Nowadays, occupational asthma is the most frequent respiratory occupational disease in the majority of the industrialised countries and it is estimated that the proportion of new cases of asthma that can be attributed to exposure at work is around 10-15%. It can be developed due to an immunological mechanism or to a non-immunological mechanism. Influential in its development are the type of agent exposed to, the level and form of exposure and genetic factors of susceptibility. In the diagnostic process there is a concurrent confirmation that the patient has bronchial asthma and that this has been caused by occupational reasons. As shown by the natural history of the disease, an early diagnosis and the consequent posterior actions result in an improved prognosis.