Applicability of a simple nasal provocation test in etiologic diagnosis of bronchial asthma.

The applicability of nasal challenge for etiologic diagnosis of extrinsic asthma was evaluated by assessing easiness of performance, precision, and cost of a standardized test by metered nebulizer in 20 asthmatics with and without concurrent rhinitis submitted also to skin prick tests and RAST. Although less sensitive than in the group with rhinitis (where precision was 90.4%), the nasal provocation test proved to be an easy, inexpensive, and specific (82.3%) means for contributing to the identification of allergic sensitization in patients affected by asthma alone.