Occupational bronchial asthma with its prevalence amounting to 14% is one of the main entities in occupational morbidity structure. Clinical evidence in recent decades demonstrates changed phenotype of occupational bronchial asthma. Changes are increased number of patients suffering from the severe asthma, higher occurrence of occupational bronchial asthma which pathogenesis is more significantly mediated by nonimmune mechanisms. Prevalence of these types of occupational bronchial asthma approaches 9.7-22%.