Background: Two types of OA are distinguished: immunological (OA with sensitization) and non-immunological, i.e., irritant induced asthma or reactive airways dysfunction syndrome (RADS). Methods: We describe the case of a worker who developed respiratory symptoms after a spill of diphenylmethane diisocyanate (MDI) at the workplace. RADS was initially diagnosed and the worker resumed working. The progressive worsening of symptoms and the appearance of symptoms-work relationship one year later, when concentrations of isocyanates were no longer "irritant," suggested immunological OA. Results: The diagnosis was confirmed by specific inhalation challenge test, followed by removal from exposure and complete recovery. Conclusions: In the case of RADS due to an agent with both irritant and sensitizing properties, history should be repeatedly assessed for a possible symptom-work relationship. If this is found, further investigations should be carried out, including specific inhalation challenges, to confirm the possibility of immunological OA.
- Diphenylmethane diisocyanate isocyanates
- Occupational asthma
- Reactive airways dysfunction syndrome
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health