Investigating nasal cytology as a potential tool for diagnosing occupational rhinitis in woodworkers

Our primary endpoint was to use nasal cytology to compare woodworkers with unexposed subjects to see if wood dust exposure correlates with specific patterns of inflammatory or infectious rhinitis. A secondary endpoint was to identify any differences in the exposed group's nasal symptoms or nasal cytology by years of exposure or personal exposure levels.

Ninety-two woodworkers and 90 controls were assessed using a questionnaire and nasal cytology (on nasal mucosa obtained by scraping). Wood dust exposure was investigated using personal sampling methods.

Woodworkers reported significantly more nasal symptoms than controls (p < 0.00001). The woodworkers' nasal smears revealed more neutrophils (p = 0.001) and significantly higher mean neutrophil scores (p = 0.001) than control smears. Lymphocytes were also found more often in the woodworkers' rhinocytograms (statistical trend, p = 0.06). Neutrophilic rhinitis was diagnosed more frequently in the exposed workers than in controls (chi-square = 5.97, p < 0.05). Woodworkers with lymphocytes in their nasal smears had been exposed to wood dust for longer periods of time (statistical trend; p = 0.06). No differences in nasal symptoms or cell counts emerged when woodworkers were stratified by levels of personal exposure.

Nasal cytology should be further investigated in woodworkers before considering it a screening method for identifying woodworkers with chronic inflammatory rhinitis.