[Reactivity of the bronchi in pollen rhinitis and pollen asthma the before and during the pollen season].

Nonspecific bronchial reactivity was investigated during and out of the pollen season in 28 pollen-allergic asthmatics and 25 hay fever patients without bronchial asthma. The degree of the reactivity was measured by the decrease of inspiratory specific airway conductance (sGI) after voluntary hyperventilation. Before hyperventilation the mean values for the sGI in both groups of patients were within the low normal range and revealed no seasonal fluctuations. During the pollen season 26 (93%) asthmatics and 14 (56%) hay fever patients showed bronchial hyperreactivity. Out of season 22 (79%) asthmatics and only 8 (32%) hay fever patients were hyperreactive. Thus, in the absence of the relevant allergens, most of the pollen sensitive asthmatics showed a significant increase in unspecific bronchial reactivity which was somewhat higher during the pollen season. The seasonal increase of bronchial reactivity in hay fever patients suggests a relationship with pollen asthma. 12 pollen-allergic asthmatics, who were examined again in the next pollen season after one period of preseasonal specific hyposensitization with pollen extracts, displayed a significant decrease in nonspecific bronchial reactivity.