Improved diagnosis and treatment of allergic rhinitis by the use of nasal provocation tests.

A simple and safe method of nasal provocation for out-patients that requires no special equipment is described. A total of 2,645 cases were tested by nasal provocation tests. Of the total, 1,175 were tested with Dermatophagoides pteronyssinus, 825 with mixed grass pollens, 352 with plantain (Plantago lanceolata), and 125 for cats and correlating nasal tests with skin tests yielded 80%, 90%, and 85%, respectively. Immunotherapy for allergic rhinitis was only considered justifiable when the nasal provocation test was positive. The nasal provocation test was repeated at the end of the normal course of injections recommended by the manufacturer. If the nasal provocation test was still positive, further injections were given until the test became negative. This method of improving diagnostic accuracy and monitoring results of immunotherapy was used with both aqueous extracts which were used for skin testing (Australian Government Commonwealth Serum Laboratories) and with Allpyral pyridine-extracted alum-precipitated extracts (Dome Laboratories, England). The number of injections of allergen required to convert a positive nasal provocation test to negative varied from 26 to 69 for mite aqueous injections with only 12 to 19 for mite suspension and 47 to 98 for grass aqueous injections compared with 12 to 36 for grass suspension. Direct provocation tests of the nose should give a more accurate diagnosis than RAST or skin tests and are required for monitoring therapy because considerable individual variations in sensitivity and response to treatment were demonstrated. Standard dosage schedules are not suitable for individual patients, who should have their immunotherapy personalized.