Objectives: The purpose of the study was to evaluate the usefulness and clinical value of the nasal provocation test (NPT) with various allergens and non-IgE-mediated irritants in the diagnostics assessing occupational rhinitis.
Methods: A large number nasal provocation data from patients with suspected occupational rhinitis was evaluated retrospectively. The results of nasal provocation tests with different agents, as well as the correlation of nasal scoring to weighed mucus secretion, were analyzed.
Results: Altogether 507 NPTs were done in three years in 165 persons. In total, 39% of the allergen provocations (125/318) were positive. The most common positive reactions were against flours, animal epithelia, storage mites and various plants. Wood dusts, mainly through non-IgE-mediated reactions, gave 50% positive results. Positive NPTs to moulds were observed mainly in sensitized patients. Altogether, 10% of the control provocations were positive. The weighting of mucus secretion added sensitivity of NPT.
Conclusions: The NPT is an essential standard tool in the diagnostics of allergic occupational rhinitis; however it needs to be evaluated in the context of the medical and work history and knowledge of sensitization. Although expensive and laborious, NPT is safe and easy for the patient. We still need reliable diagnostic tools for non-allergic work-related rhinitis.