Nasal blown secretion evaluation in specific occupational nasal challenges

To investigate the usefulness of nasal blown secretion evaluation during specific nasal provocation test (sNPT) in diagnosing occupational rhinitis (OR). To validate the method, nasal blown secretions from 103 healthy subjects and 30 allergic rhinitis patients were analyzed. Furthermore, we analyzed nasal blown secretions, collected before and after sNPT, of 29 subjects with work-related rhinitis symptoms (WRRS) who underwent the diagnostic pathway for OR. Rhinoscopy and nasal symptom score were used to define a positive sNPT. A total of 89.6% WRRS subjects provided suitable nasal secretions. Eosinophils significantly increased after positive sNPTs compared to negative ones (P = 0.006). Four percent and/or 1 x 10(4) eosinophils/ml was the cut-off for a significant post-sNPT eosinophil increase. A total of 4/13 (33%) WRRS subjects with negative sNPT, assessed by rhinoscopy and nasal symptom score, presented a significant post-sNPT nasal eosinophil increase, and were identified as possible OR. Eosinophil evaluation in nasal blown secretions is an important tool in monitoring the response to occupational specific nasal challenges.