[Problems of occupationally induced respiratory allergies as exemplified by bakers' asthma]

In the Federal Republic of Germany (FRG) approximately every fourth case of occupational lung disease, registered with application for compensation at the "Gewerbliche Berufsgenossenschaften", in 1984 was suspected to be caused by allergic airway obstruction. Respiratory allergies may arise if two prerequisites exist firstly exposure to sensitizing agents in the work environment and secondly individual disposition to allergic reactions. The large range of sensitizing agents includes organic and inorganic substances derived from animals, plants, fungi, metals or chemicals. Most of them are responsible for Type-I IgE-mediated allergic reactions. Three different patterns of respiratory responses can be found following simulated occupational exposure: immediate, late (non-immediate), and the dual-type of asthmatic reaction, whereby the non-immediate asthmatic response must be strictly differentiated from the genuine Type-III hypersensitivity. Today, bakers' asthma is the most frequent and most costly occupational allergy in the FRG, contributing more than 50% of all registered and more than 75% of all compensated cases. Therefore, flour allergies can be used as a classic model of an occupational allergic disease in order to discuss epidemiological, social and clinical problems, such as prevalence, socioeconomic impact, as well as prevention, early diagnosis and therapeutic measures. Despite many well-known clinical and epidemiological data, respiratory allergies display a lot of unresolved questions calling for further research.