Introduction Isocyanates are strong respiratory sensitizers. Repeated and prolonged occupational exposure to these molecules is currently one of the leading causes of allergic asthma and rhinitis in the workplace.

Objectives Describe the socio-professional, clinical, functional and allergological characteristics of cases of asthma allergic to isocyanates, and assess their impact on medical fitness for work.

Methods Retrospective study covering all cases of occupational allergic asthma and rhinitis to isocyanates collected from the Department of Occupational Medicine of La Rabta hospital during the period from January 2000 to July 2020.

Result: This is a series of 26 patients with a mean age of 42.62 ± 9.01 years, including 19 women and 7 men. The majority belonged to the automotive sector (19 cases). They were mainly workers responsible for gluing and sheathing the steering wheels (16 cases). The average seniority in the post was 12.88 ± 6.01 years. The lack of personal respiratory protection was reported by the majority of patients (24 cases). The first functional manifestations appeared on average 8.15 ± 5.13 years after exposure, dominated by nasal pruritus and rhinorrhea (16 cases) and wheezing dyspnea (5 cases).Rhythmicity with work was reported by all patients. The physical examination revealed a congestive mucosa (3 cases) with severe obstruction (1 case). Reversible obstructive or airway hyper reactivity was confirmed in 11 cases. Finally, we identified 15 cases of allergic rhinitis, 7 cases of allergic asthma and 4 cases of rhinitis associated with asthma. This morbidity justified an adaptation of the workstation in 12 patients and a mutation of the post in 12 cases. the majority of patients (23 cases) benefited from a declaration of this morbidity as occupational disease.

Conclusion Occupational exposure to isocyanates represents a significant allergic risk. This risk remains avoidable by putting in place appropriate individual and collective preventive measures.