Objective: To examine the utility of specific inhalation challenge (SIC) in assessing the nasal congestive response to isocyanate exposure.
Methods: Nine patients complaining of work-related respiratory symptoms underwent SIC with exposure to isocyanate for 4 and 120 minutes on different days. Nasal volume was monitored by acoustic rhinometry and nasal congestion by the visual analogue scale (VAS) for up to 6 hours.
Results: The 4-minute isocyanate SIC induced a nonsignificant fall in nasal volume and no increase in the VAS score. The 120-minute isocyanate SIC induced a significant fall in nasal volume at 15, 30, and 60 minutes postchallenge that was associated with a significant increase in the VAS score at 15 and 30 minutes postchallenge.
Conclusions: SIC appears useful to assess changes in nasal patency after exposure to isocyanate. Exposure to isocyanates can induce nasal congestion that can be objectively monitored during SIC.