Occupational rhinitis in workers investigated for occupational asthma
- 1Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- 2Department of Chest Medicine, Hôpital du Sacré-Cœur de Montréal, Quebec, Canada
- Dr R Castano, Hôpital du Sacré-Cœur de Montréal, Centre de Recherche-Pneumologie, 5400 Gouin Blvd West, Montreal, QC, Canada, H4J 1C5;
- Received 7 June 2008
- Accepted 29 August 2008
- Published Online First 3 October 2008
Background: The links between asthma and rhinitis are now referred to as united airways disease (UAD). Current evidence shows that the UAD model seems to be applicable to occupational rhinitis (OR) and occupational asthma (OA). A study was undertaken to objectively assess, in the context of specific inhalation challenge (SIC) testing, the concomitance of bronchial and nasal reaction in the investigation of OR and OA.
Methods: 43 subjects with a history of work-related asthma symptoms underwent SIC for confirmation of OA and investigation of OR. Changes in bronchial calibre were measured by spirometry and nasal patency and airway inflammation were assessed by acoustic rhinometry and nasal lavage.
Results: A positive nasal challenge was observed in 25 SIC tests and a positive bronchial challenge was observed in 17 SIC tests. A concomitant positive nasal and bronchial challenge was observed in 13 instances. This association was significant (risk ratio = 1.7; 95% CI 1.0 to 2.4; p = 0.04) and more frequent in subjects challenged with high molecular weight agents (n = 11/22) than with low molecular weight agents (n = 2/21). In subjects with a positive nasal challenge, nasal lavage showed a significant increase in eosinophils 30 min after exposure which correlated with changes in nasal patency.
Conclusion: The results of this study provide objective evidence to support the concept of UAD using OR and OA as a model to demonstrate a significant concomitant physiological reaction of the nose and lungs after challenge. This study shows that OR can be assessed by objective means; it often coexists with OA but can be present without OA.
▸ Additional details of the design of the study are published online only at http://thorax.bmj.com/content/vol64/issue1
Competing interests: None.
Ethics approval: Ethical approval for the study was obtained from the hospital medical ethics committee.