Nasal provocation test in the diagnostics of occupational allergic rhinitis.

The diagnosis of occupational rhinitis (OR) must be better confirmed than in allergic rhinitis of other aetiology. A provocation test is required to confirm the causality between the disease and the work exposure. The purpose of this study has been to examine the feasibility of active anterior rhinomanometry and visual analogue scale in the diagnostics of OR, and to compare the results of these measurements to a nasal status change score. The study subjects have been 50 consecutive patients suspected of having OR. Altogether 148 bilateral nasal provocation tests (NPTs), 55 placebo- and 93 allergen-NPTs, have been done. Based on the change in the nasal status and change in the nasal airway resistance (NAR), there are 42 positive NPTs. Although overlapping between placebo and allergen provocations exists, an increase of > 50% in NAR is recommended to regard the result as positive in NPT. The evaluation of the nasal reaction in the NPT is mainly based on anterior rhinoscopy and the change in the status score, but OR diagnostics should also include some physiological measurement.