Seasonal asymptomatic lower airway hyperresponsiveness in patients with allergic rhinitis

Allergic rhinitis is considered a risk factor for bronchial asthma. It therefore seems essential to identify patients threatened with this disease in whom no disturbing bronchial symptoms have occurred. The study's aim was to evaluate the incidence of nonspecific bronchial hyperactivity based on exercise results in pollinosis patients.

The study group comprised 27 patients with seasonal allergic rhinitis allergic to tree pollens but without asthma symrptom. Exercise provocation tests were performed before, during, and after completion of the pollination period. During the pollination period, specific IgE (sIgE) and nasal eosinophilia were also determined. Twelve patients allergic to Artemisia pollen made up the control group. The results were also evaluated in relation to desensitization therapy.

In the study group a pathological result of the provocation test was obtained in 1 patient (3.7%) before the pollination period, in 7 patients (25.9%) during, and in 4 patients (11.8%) after its completion. The subjects with a positive test result had higher levels of nasal eosinophilia, while there was no relation between the result and sIgE levels. Only one case of positive exercise challenge was identified among the desensitized patients.

During the pollination period, nonspecific bronchial hyperreactivity develops in some patients with seasonal allergic rhinitis; it can be sustained for some time after the disappearance of pollens from the atmosphere and can he identified using an exercise challenge. Incidence of bronchial hyperreactivity in desensitized patients was lower than in those subjected to symptomatic treatment.