[Occupational asthma: retrospective study of a series of 144 cases]

The occupational origin of asthma is only found only late, from a diagnosis delay due to development. The aim of this work was to study the chronological characteristics of occupational asthma of different etiologies and to understand the occupational after-effects. A series of 144 cases were analysed (115 men and 29 women) who were seen in a consultation that specialised in occupational pathology, with the inclusion criteria those of the National Institute for Occupational Safety and Health (NIOSH). The analysis was based on: the causative allergen or work protocol; the role of atopy; length of the latency phase; length of symptom exposure; diagnosis delay; occupational consequences. Asthma from isocyanates and flour between them accounted for 62% in this series. These were followed by asthma from wood (8.3%) and persulphates (7.6%). The mean length of the latency period was 7.5 years and the mean diagnosis delay was 2.5 years. Clinical history of atopy and the existence of rhinitis were much more common for the "biological" than the "chemical" asthmas (respectively 69% and 95%, against 36% and 15%). Amongst the 64% of patients who benefited from complete removal of the allergen, 78.5% who were cured or improved, though for those who kept the same conditions of work there was a persistence or even aggravation of symptoms. In 74 cases a certificate of occupational illness was given to the patient.