Background Initial attempts to evaluate the association between allergic rhinitis and nonspecific bronchial responsiveness has produced conflicting results. In fact, some studies showed a strong correlation and other failed to find an association. However, little is known about the effect of natural specific allergen exposure on the bronchial reactivity of mono-sensitive patients with rhinitis in the southern Mediterranean area, in relation to skin reactivity to allergens, total serum IgE levels and blood eosinophiis.
Objectives The significance of the association between allergic rhinitis, and abnormal airway responsiveness with regard to the pathogenesis of asthma is unclear. For this reason, we have studied non-specific bronchiai hyperreactivity. in patients with seasonal allergic rhinitis, with reference to the responsible allergen. The aim of the study was to correlate the responsiveness to bronchoprovocation with methacholine in subjects a with allergic rhinitis during and out of the pollen season with total serum IgE and blood eosinophils.
Methods Fourty-nine non-smoking patients with clinical diagnosis of allergic rhinitis and mono-sensitive skinprick tests to pollen allergens were enrolled in the study. Twenty patients suffered from seasonal rhinitis to Parietaria pollen. 15 patients to Gramineae pollen and 14 patients to Olea pollen. In all patients lung function measurements (assessed as response to methacholine). tolal serum IgE and blood eosinophii counts were measured during and out of the pollen season.
Results During pollen season. 16 out of 49 rhinitis patients demonstrated values of bronchial responsiveness measured as response to inhaled metbacholine in the asthmatic range whereas out of the pollen season only eight patients were in the asthmatic range. By analysing the results with reference to the responsible allergen, during the pollen season 5 out of 16 patients were Parietaria -sensitive and out of the pollen season seven out of eight patients. Finally, in Parietaria -sensitive rhinitis bronchial responsiveness signifi-cantly correlated, during and out of the pollen season, with total serum IgE and with blood eosinophil counts.
Conclusions Our results are consistent with the hypothesis that Parietaria is more important than Olea and Gramineae as a risk for developing non- specific bronchial hyperresponsiveness. On the whole, present observations provide further evidence that there is an interrelationship of allergen kind, total serum IgE. eosinophil and bronchial hyperressponsiveness suggesting that they may play a role in the development of bronchial asthma in rhinitis patients.