Changes in nasal lavage fluid due to formaldehyde inhalation

The aim of the study was to characterize the nature of the formaldehyde-induced nasal response consisting in symptoms of rhinitis and changes in nasal lavage fluid. Eleven healthy subjects and nine patients with specific skin sensitization were provoked in a toxicological chamber with formaldehyde at a dose of 0.5 mg/m³ over 2 h. Nasal lavage was performed prior to and immediately after provocation and 4 and 18 h later. Provocation with formaldehyde caused transient symptoms of rhinitis and prolonged changes in nasal washings. There were increases in the number and proportion of eosinophils and elevated albumin and total protein levels in nasal lavage fluid 4 and 18 h after provocation. No difference in the nasal response to formaldehyde was found between patients with skin sensitization and healthy subjects. These data confirm the irritative effects of formaldehyde and are also suggestive of nonspecific proinflammatory properties when formaldehyde is inhaled at a low (0.5 mg/m³) dose.