Occupational exposure to toluene diisocyanate and neutrophilic bronchitis without asthma

Isocyanates represent a leading cause of occupational asthma, and sputum neutrophilia or eosinophilia has been described in subjects with isocyanate-induced occupational asthma after exposure to these chemicals. One case of non-asthmatic eosinophilic bronchitis due to methylene diphenil isocyanates has been reported, but a similar condition in the instance of neutrophilic bronchial inflammation has never been described.

We report a 34-year-old woman, who, 18 months after beginning work in a plastic industry, reported the onset of dry cough at work. Spirometry was normal, reversibility and methacholine challenge tests were negative. A specific inhalation challenge with toluene diisocyanate elicited dry cough without significant changes in respiratory function. Sputum induction showed a post-challenge neutrophil increase.

The results of our case suggest that the occurrence of a neutrophilic bronchial inflammation without the functional characteristics of occupational asthma as a consequence of exposure to toluene diisocyanate may also be considered, suggesting a diagnosis of occupational non-asthmatic neutrophilic bronchitis.