occupational asthma

Occupational asthma is asthma that is caused, or made worse, by something a person breathes in at work. A classic clue is timing: the wheeze, cough, chest tightness and breathlessness worsen on workdays and ease on weekends or holidays, only to return when the person goes back to the job.

There are two main routes. In sensitizer-induced asthma, repeated exposure to an agent — flour in bakeries, isocyanates in paints and foams, latex, wood dust, or animal proteins — provokes an allergic-type immune response, so that after a latency period even small amounts trigger attacks. In irritant-induced asthma, a high-level exposure to a corrosive gas or fume (sometimes a single accident) inflames the airways and leaves them hyper-reactive, without a prior sensitizing period.

Diagnosis links the asthma to the workplace using a careful history, serial peak-flow records kept at and away from work, and sometimes specific challenge testing. The cornerstone of treatment is removing or greatly reducing exposure, ideally early, because continued exposure can cause permanent airway damage. Standard asthma inhalers control symptoms, but they do not substitute for addressing the cause.