Predictive value of airway resistance in patients affected with pollen rhinitis.

We selected 38 symptomatic pollen-sensitive rhinitic patients without bronchial pathology and with normal pulmonary functional study (volume flow curve). A control group consisting of 10 individuals was studied adjacently. The study was performed within the pollen season. The determination of Raw value was carried out through increasing doses of histamine challenge employing the Apta-Jaeger apparatus. The results were expressed in PC20 wherein 26% of the pollen-affected patients presented bronchial hyperreactivity (positive histamine bronchial provocation test). In this group the values of basal Raw were found to be increased with respect to the control group (p less than 0.025) and pollen-sensitive patients with negative histamine bronchial provocation test (p less than 0.01). On the other hand, the pollen-sensitive group with negative response to histamine bronchial challenge presented Raw values which were similar to the control group.