Occupational asthma has become the most common pulmonary disease in developed countries. About 250 substances can cause occupational asthma. Isocyanates are the cause of the most common form of this disease. The incidence of isocyanate-induced asthma among workers exposed to this substance is close to 10%. The mechanisms of pathological lesions in occupational lung diseases are listed in the table below.
a) Classification of occupational asthma . There are 2 categories of asthma in the workplace: occupational asthma and asthma worsening due to working conditions. Occupational asthma is characterized by a greater or lesser limitation of airway patency, bronchial hyperreactivity, or both, which is induced by the conditions of a particular working environment, but not by irritants outside the workplace.
Asthma, exacerbated by working conditions , is asthma that has developed earlier, or concurrently existing asthma, which is aggravated by stimuli or physical factors in the workplace. Occupational asthma can develop in a person with pre-existing asthma or concurrent asthma after exposure in the workplace.
There are 2 types of occupational asthma, depending on the presence of a latent period. The most common type is occupational asthma with a latent period. It develops after a certain period of exposure, which can vary from several weeks to several years.
Occupational asthma with a latent phase includes all cases of immunological asthma, although for some substances the immunological mechanism has not yet been identified. Occupational asthma without a latent period occurs after exposure to high concentrations of irritating gases, smoke or chemicals in one or more cases. A systematic approach to collecting medical history and diagnosing a disease induced by the profession and the environment is shown schematically in the figure below.
b) Treatment of occupational asthma . An ideal treatment for patients with occupational asthma with a latent period is removal from the site of exposure. In most cases, people with occupational asthma must undergo retraining and find a new job in another field of activity. A patient with occupational asthma returning to their previous place of work should be closely monitored by a physician. In case of exacerbation of asthma, immediately leave the place of exposure. Pharmacological treatment is similar to treating patients with other forms of asthma.