D2.115 - Occupational asthma and rhinitis to isocyanates in industrial settings

Isocyanates are respiratory sensitizers widely used in industrial settings and represent a frequent cause of occupational allergic asthma and rhinitis. The aim of our study was to describe the occupational and clinical characteristics of occupational allergic asthma and/or rhinitis related to isocyanate exposure, and to assess their impact on medical fitness for work. 

A descriptive cross-sectional study was conducted on medical records of patients who consulted the occupational medicine department at La Rabta Hospital in Tunis between 2003 and 2025 for occupational allergic asthma and/or rhinitis due to isocyanates.

The study included 31 cases, with a female predominance (68%). The mean age was 42.06 ± 8.95 years. Most patients worked in the polyurethane automotive steering wheel manufacturing industry (58%), followed by automotive filter manufacturing (3%) and automotive painting (3%). The mean occupational seniority was 12.48 ± 5.5 years. Personal respiratory protective equipment were not used in 81% of patients. Clinical manifestations appeared after a mean latency of 7.68 ± 4.54 years, occurred on workdays improved of leaves in all cases. ENT examination, performed in 23% of patients, revealed nasal congestion in 10% and nasal hyperreactivity in 3%. Spirometry, performed in 87% of patients, showed reversible obstructive ventilatory impairment in 10% of cases. Methacholine challenge test was performed in 71% of patients and was positive in 52%. Overall, 48% of cases had allergic rhinitis, 32% had allergic asthma, and 20% combined rhinitis and asthma. These allergies were considered as compensable occupational diseases in 87% of cases. Workplace adjustments were implemented in 45% of cases, and job reassignment was required in 39% of cases. 

Occupational exposure to isocyanates causes significant allergic respiratory morbidity. Early diagnosis, collective and individual preventive measures, and prompt occupational management are essential to reduce its impact.