[Occupational asthma: current and future perspectives. The point of view of an expert]

Occupational asthma remains a difficult problem for physicians and for experts. The prevalence of occupational asthma is underestimated and depends on industrial agent and conditions of work. Diagnosis is made based on detailed description of the patient's work environment, on skin and serological tests, and on lung function tests including non-specific bronchial provocation tests. Rhinomanometry, and peak flow rate measurements may also be useful. Bronchial provocation tests should be performed by experienced staff in a hospital setting with facilities for resuscitation. The prognosis of occupational asthma is variable: --some patients with short and limited exposure may fully recover if their disease is early recognized and appropriate measures are taken; --however, many patients do not recover completely after removal of the responsible agents. Clinical symptoms and bronchial hyperreactivity persist and respiratory insufficiency may develop. The patterns of occupational asthma are changing rapidly, in parallel with industrial evolution: nowadays, bakers's asthma is less frequent than it used to be. Asthma triggered by wood dust and in particular western red cedar (which is exported all over the world) is increasingly recognized. Isocyanates and, in particular toluene isocyanate, are widely used in plastics and paints. Preventive measures have succeeded in decreasing the incidence of asthma caused by exposure to isocyanates. Computer industry has recently developed in many countries. It requires the use of numerous hazardous and highly toxic materials that are potentially responsible for occupational asthma; attention should be given to respiratory diseases especially in industrializing countries (such as Eastern Asian countries). Preventive measures include safety rules, replacement of harmful materials by less toxic agents and detection of susceptible workers. Regulation must be defined under experts' control to continuously match the rapid changes in modern industry.