Modified method of nonspecific nasal provocation with histamine for routine use.

An improved method for assessment of nonspecific nasal reactivity (NNR) was evaluated to validate it, and determine a criterion for nasal hyperreactivity. The efficacies of four different parameters to indicate nasal patency in assessment of the level of NNR were compared in 60 healthy subjects and 65 patients with allergic rhinitis (37 in the period of pronounced symptoms and 28 in the symptom-free period). Histamine/diphosphate was sprayed into both nostrils every three minutes in doubling concentrations (0.03125 to 32 mg/mL); during 90 seconds, sneezes were counted and symptom score was assessed; thereafter nasal inspiratory peak flow (NIPF), total nasal airway resistance (NART), nasal forced expiratory volume in one second (N-FEV1) and nasal midexpiratory flow rate (N-MEF25/75) were measured. Nasal inspiratory peak flow meter (Youlten, "Airmed") was used to measure NIPF. A spirometer (Pneumoscreen II, "Jaeger") with a face mask attached was used to measure NART, N-FEV1, and N-MEF25/75. The test of NNR was terminated when a significant change of values (as determined by a pilot study) occurred: NIPF, -30%; NART, +75%; N-FEV1, -20%; and N-MEF25/75, -25%. Our results indicate a significantly higher NNR (PCNART of patients = 0.77 mg/mL versus PCNART of healthy subjects = 4.5 mg/mL; P < .00001) period of pronounced symptoms than in healthy subjects or in rhinitic patients when symptom free. A criterion, that takes age into account, is set for separation of normoreactivity from hyperreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)