To examine the utility of specific inhalation challenge (SIC) in assessing the nasal congestive response to isocyanate exposure.
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.
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.
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.